I don't blame you for doing something

Từ điển Oxford Advanced Learner 8th

I don't ˈblame you/her, etc. (for doing sth) idiom
(informal)used to say that you think that what sb did was reasonable and the right thing to do
•‘I just slammed the phone down when he said that.’ ‘I don't blame you!’
Main entry: ↑blame_idiom