I wouldn't make something up, but you can usually hammer a story into a mould when the need arises. I've never worked with someone I'd call a douchebag, but I've certainly worked with people who have frustrated me by actions like not responding to e-mails, forgetting requests to do things that were their job, and suchlike.

Given this loose criteria, if you tell someone you've never fucked up, and you've never worked with a douchebag, and you've never disagreed with someone at work, they might think you don't have experience working in a medium-sized-or-larger company; or you had managers that insulated you extremely well; or you don't have much self-awareness.