There's a difference between rationalizing away feelings and giving someone the benefit of doubt. In my experience, the other person's intentions play a role. I've been learning to temper my anger reactions by asking if I actually know the intentions of others or if I'm making an assumption about what another person's reasons are for saying or doing something. And my reactions (anger, sadness, fear etc) need to be at a level that matches someone's intentions. If I don't know what the other person intended when they said or did something, I don't know what my reaction should be.
It may be cliche and corny, but I use "I feel (blank) when (blank)." And actually ask the other person what their intentions are. Its helped me quite a bit in healing certain traumas, avoiding ptsd triggers that still exist and to identify toxic people in my life (by toxic I mean they negatively impact my wellbeing).
When I'm starting the difficult conversation or facing what could be an unpleasant reaction by someone else, I start by telling them it isn't my intention to hurt them and I don't want to assume that what might be difficult for me will be difficult for them. I give them the benefit of the doubt that they have their own issues without rationalizing away any impact it has on me and how I feel.