If it was from his own account, that would be one thing. But he specifically pulled it from the joint account, which means he took from the household and he used op's contributions for it without any discussion.

op specified he's on disability so either a) he has very little coming in so needs op's share in a joint account, or b) op's saying this to make things sound worse.

but i don't think that's really matters, whatever the circumstances, this was not cool.