He's treating you like a child.
You were worried you would be told off about damaging the car (not "his" car, you call it "our" car) and his the damage, so you could present it in a better light. So, you are buying into his attitude of superiority to you within the relationship.
I once drove down the road and clipped the wing mirror of our car. I was mortified and worried about what DH would say, and was somewhat nervous when I "owned up".
Once I had told him, he said breezily, "oh yes, I've done that a few times".
So, I realised that I felt I had to "own up", but when he had done something similar, he didn't even feel he needed to mention it to me.
This really made me think about our dynamic, and I realised that no one can make you feel inferior without your permission. (Eleanor Roosevelt, said that, I think.)
You don't have to feel like a guilty child, and you don't have to hide accidents from your DH. Accidents happen to everyone. If you have a regular pattern of accidents like this, maybe you need to take more care, but you don't mention it.
Your husband sounds very controlling (you say perfectionist - I think that's a euphemism for "controlling arse").
Call him on it. "Why are you treating me like a child? Accidents happen. I'm sorry I hit the pillar and it's going to cost us money, but it didn't mean to, and everyone makes mistakes at times."
Unless you think you will be "punished" in some way for calling him on it. In which case, reevaluate your relationship.