My past experiences are filling in the blanks, which may be inaccurate, hence why I don't make assumptions. I determined what I did from the pictures using inductive reasoning. In the 30 or so pictures she posted, she looks like she's having a good time, and the ex isn't in any of them. In the two that he posted, she does not look like she's having a good time, and he did not post any other pictures from that night. There's also the factor that he took the pictures himself. I've been to a lot of different bars on many occasions, and 99% of the time, people simply ask someone nearby to take a picture rather than opting for a selfie. People are usually willing, and it usually results in better quality pictures. The only advantages to taking a selfie in a crowded bar is that it gives others less of a chance to object to a picture being taken, and there's the possibility it wasn't be noticed. This is enough evidence to find him being guilty of being a douche.
You say this is not "assumption" but "inductive reasoning" and elsewhere you say other things are not assumptions but speculation.
Speculation this may be, but it is negative hyperbolic speculation. It is over analysis. I'm going to assume you see your over analysis tendencies as a personality trait based on other posts you've made but honestly it is not doing you any favors. It is not some kind of neutral thing because it has affected your emotions, gotten you all worked up AND has allowed you to feel free to label some guy you do not know a "douche" all because you have inductively reasoned him to be via a convoluted story you have constructed from some photos. I bet if you were secretly in love with the guy you could have constructed a story from those photos that was completely different.
I know you are most likely to answer defensively and tell me why this is all wrong as you told most people why they were all wrong in your replies. But I hope you will think about how over analysis works. Though it can be a fun game to play once you are actually worked up about it and judging others based on it you are losing your grip on your brain wheels spinning too fast. It's clear you have very little information about the woman, her past relationship or the ex boyfriend and your mind is trying to fill in all the blanks. You may well think this is fine because you intend to replace your "inductive reasoning" facts with any new facts that come along and disprove them. And as I said, if this was all a 'what if' game it wouldn't matter but the fact is it's made you angry and worked up and caused you to dislike someone and label them a douche and maybe abuser.
It can be very peaceful and freeing to say "I don't know anything. I will just ask." You are worried about how that comes across, well if any woman had a glimpse of this whole thought process you reveal here believe me that
would come across a whole lot worse. If someone else is freaked out by you simply saying, "hey I like you, what's the deal with the ex? and can we go out sometime?" then obviously it's not going to work out anyway.
As to anxiety asking women out, I would say to anyone always understand that there is no way to tweak the setting and situation for asking someone out so that it is within your comfort zone. Accept that it is going to take you outside of your comfort zone and it's going to cause some stress and possible hurt and then just walk forward and do it.