There problem I see here is a lot of "I" in these statements. Being able to seperate yourself from your character when actions that adversely affect your character arise is important. In my opinion the biggest problem I see here is that YOU were personally upset when their characters reacted equally in character to yours, but did not fall in line with your ideas.
Your character acted in character(in your opinion), their characters reacted in character(in their opinion) and part of that reaction was not approving of your in-character actions. You then became upset that they disagreed with you, which is fine IN CHARACTER, but from reading this it feels like you became upset with the PLAYERS as a fellow player.
So yes, while the setting may be whatever, I think the issue here is that players(yourself and them) are not separating themselves from their characters while role-playing.
<sigh> Your attention, please. This is the DM speaking.
Yes, the issue IS players not being able to separate themselves from their characters. But, here is the twist on that. Although I have, time and again, harped on the difference of the gameworld mindset, I have one player who consistently refuses to play to that mindset, insisting on a modern ethics-based epistemology. And the third player is a "do as I say, not as I do" style player. In other words, he gets very upset when another player does or says something HE considers as possibly causing either inner-party conflict, or potentially causing the party problems. (He, on the other hand, can do or say anything he sees as being in character, regardless of the consequences, and that is okay.)
The one watchman acted and spoke in a way that would be very out of character for the City Watch, especially since the Elf Witch's character had cast a spell in their sight, and was wearing a medallion with her Guild's emblem (a guild that is rather feared by the city's underbelly and lesser authorities). As usual, Elf Witch was the only one to pick up on the clue, and follow up on it. The other two decided that she was indulging in theatrics and, in disgust, walked off. One of them even had the gall to make the parting remark of, "She does this all the time." (Side note: The character had been travelling with the party all of about four weeks, and this was actually the second time they all were interacting with local authorities. The other time, Elf Witch's character was polite to the mayor, local church prelate and Watch Captain.)
BTW, the explanation I got for their behavior was that the party was supposed to be trying to keep a low profile, and hide their presence while in town, to avoid their enemies. Although how you can hide a heavily shadow-tattooed dwarf and a furred, winged 6'+ humanoid is a bit beyond me. As for enemies, I had already told them that their one enemy had been exiled, and the other one seemed to have also quit the city.
There are two core problems. One problem is that no one seems to be able to accurately remember background and past events. Elf Witch takes notes at the table, and regularly reviews them. The other two don't, and then resent the fact that Elf Witch does remember things when they don't.
The other problem I have is the refusal to live in the world I have created. It seems that I rarely have two sessions go by where there is not an argument about what is and isn't acceptable alignment behavior, and past incidents are brought up time and time again as examples, even when I have ruled them as correct. For example, I have emphasized that, when it comes to sapient creatures, there is no hard, fast alignment. Yet time and again, one or the other of my male players make assumptions based on metagame knowledge gleaned from the Monster Manual or past experience (and I'm not talking PC experience, either.) And then they are unpleasantly surprised when their assumptions bite them in the ass, and once more the arguments start.