Love it.
The process is always: thought, feeling, action.
So the emotion is never 'wrong', it's simply the consequence of a thought process. Thought processes however can be wrong, and are the thing we need to focus on examining.
We can reverse engineer the feeling like you say, by observing the emotion and then asking "What must I be doing inside my head in order for me to end up generating this emotion?".
Our perspective on reality may end up being accurate, in which case the emotion is justified, however more often than not we judge a situation based on very little information.