I think the problem here is that you're using the word 'fault', when you simply mean that you believe the OP wasn't always entirely professional. They do have different implications. Cani himself admits he wasn't always on his best behaviour, but he never did anything that would put him at 'fault' for not getting his suit.

Hopefully that made sense and explains why people are asking you how he was at fault. They're not asking you what you think he did wrong, they were asking you how you think he contributed to the loss of his suit.