It's good to make things practical. Having a real life example is really helpful.
There is a lot of different things that could be addressed here: 1. someone was lying to you (half-truth), 2. being confronted with 'done-deals' after the fact, 3. the kamma of another, 4. addressing the issue at all or not, 5. the feelings of the other person, 6. baring consequences, 7. not wanting to be critical, 8. others not knowing how to be skilful
Maybe you see more issues I haven't been able to pick up.
I try to address the things one at a time.
1. someone was lying to you (half-truth)
This is one I encounter on a regular basis lately as well. As far as I can see there are two sides to this coin: the being lied to and my reaction to this. One of my teachers said to me something like: "Why are you disappointed that others lie to you? What did you expect? Only sotapanna's and higher no longer lie."
That did hit home. Indeed, everyone lies. Or, better yet, is incapable of not lying. Unless sotapanna or higher. I'm not talking about intentional lying, btw. But, even if they don't know, it's still lying. But, my teacher is correct: the problem is my unrealistic expectations of other beings. It's the expectations I have to adjust. It is unfair of me to expect 'behaviour of an arahant' from people that might not even meditate.
Maybe you can look into that one as well.
2. being confronted with 'done-deals'
In short: what's done is done. Letting go of what has been done would be the wise reaction, imho.
Investigation ones own reaction is the thing here, I'd say. Does it bother you? If so, why can't you let go of it? Is there a sensation of pressure, restlessness, anger, etc? That should be dealt with, since what another person does is really not in your control.
3. the kamma of another
Also, neither in your control nor is it, quite frank, your business. (Sorry, English is not my first language and sometimes I don't know how to phrase things differently.)
But, I must also say that this training in 'not interfering with another' is quite hard. At least for me. Imho, it's a training for the higher paths.
What I discover in myself is that this 'entangling with another's speech or action' is deeply engrained. My teachers' advice was: "Don't entangle yourself with the kamma of another person." It's easier said than done, imho. It raised a lot of questions in me: "Why not?", "When do I entangle myself anyway? How would I know?", "How do I stop entangling myself?", etc.
I would give you the advice of my teacher: don't get entangled. Since this is some issue I haven't dealt with completely myself, that's all the advice I can give.
4. addressing the issue at all or not
This one, I think, depends on different things. Did it make things really difficult for you in a practical sense. Did his/her action put you in a difficult position? Then, you can address that bit. Is it likely to happen again and is said person able to correct his/her view on this issue? Then, you can address it. Maybe you can think of other reasons (other than your own internal world, because that is on you) that would be a reason to address it.
I would also refer again to the fact that we shouldn't expect things the other is unable to do (ie. expecting 'arahants' behaviour').
But, do you really have to do anything at all? More often than not I find that with reacting/responding I just give more power and momentum to things. And I start to wonder whether doing nothing isn't more skilful in most situations. Let things burn out. When I asked a teacher when I should act his response was that I should act in case of danger of harm for myself or others or when I can. But, even if I might want to it doesn't mean that my reaction has any impact at all. The workings of the law of kamma, right. The result of bad kamma of the other being might be in the way of making any difference or being helpful. And we simply can't know whatever kamma of others comes to fruit at a certain point.
We should, however, never ever react out of unwholesome states.
Which brings me to a question. You seem to struggle with the question whether to do something or not. Which means, that there is doubt. Since doubt is unwholesome, a hindrance wouldn't in this case the best action to not do anything? Except figure things out for yourselves, of course.
(I don't need an answer, btw., since it wouldn't be useful for me at all. So, it's more meant for reflection.)
5. the feelings of the other person
Well, that is again, not on you. Their feelings are theirs. The way they will react has to do with their own conditioning. You can't prevent or protect them from this. 'Each is the heir of their own kamma', comes to mind here.
6. baring consequences
To each his/her own, I'd say.
The way we react to situations is the problem. Since we can't control others' actions it is up to us to learn how to respond in a skilful way. Being honest with oneself is one of the most crucial skills to develop, imho. And being patient with oneself and others. The other 8 parami come to mind here as well.
7. not wanting to be critical
Why not? You are allowed to be critical. Monks have to 'correct' each other as well in monasteries. The advice here is that one should use the right speech for those occasions. Right speech has 5 characteristics:
- Is what your saying (or going to say) true? If yes, then say what you want to say.
- Is it beneficial/useful for the other person? Yes? Go ahead.
- Is it timely? Don't wait ages to address the issue. But also, is it the right time? Are you, f.i., alone with the other person?
- Is it polite? Don't be insulting to the other person. Address the way you formulate what you want to say.
- Is it kind? Here, the sandwich method you were referring to, comes to mind. I would start with showing a lot of appreciation for the intention of the other person. Say that I could see that (s)he didn't mean any harm or wrong doing. Things like that. And then explain why it wasn't skilful and how things could be done more skilful in the future.
Does that make sense?
8. others not knowing how to be skilful
None of us really know how to be skilful, I'd say. Developing wisdom by looking at ones own mind is the start here, imho. Cause, really, what is being skilful at all? If I look at myself, I must admit that in a lot of situations I don't even really know. How on earth can I then be so arrogant to assume to be able to judge that another person isn't skilful? (This might, btw., absolutely not be applicable to your situation. I just write down what comes to mind.)
The more wisdom there is, the more compassion grows. Towards others, towards myself.
Nowadays I really try to not look at what others say or do at all since I myself am not 'done' yet.
When something happens, someone lies to me, f.i., first I look at my own reactions. See where work is still to be done, what hindrance needs to be worked with. Then I try to let the issue 'simmer in its own juice', so to speak. If, after a short while, I come to the conclusion that I actually can give some useful advice, that I actually do have an answer to what is skilful or not, then I can still address it.
Anyway. As you can see, there really is a lot to unpack. Coming to know ones own intention might be the hardest of them all. Do I want to say anything because it bothers me (and I use deflections and projections to cover this) or do I really think it would be helpful for the other person? It requires total honesty. But, we also shouldn't expect things we can't live up to yet, from ourselves. Compassion not just for the other person, but also for ourselves is a good practice.
I hope any of this can give you a spark, an idea, an inspiration. Keep what you can use, throw out the rest. And, just to be sure, I didn't mean to be harsh or offend in any way. I really struggle sometimes with correct use of English language.
P.S. You might be right about the bit about it being a semantics issue. That thought occurred bo me as well. Also, I appreciate this conversation with you. It makes me reflect on my own progress and things that still need to be developed. Thank you for that.