"I'm angry and angry. I thought we were terrible. We made so many basic errors. I'm furious. We can talk about injuries and about various different things but I'm annoyed," he told reporters.
"When you have a bloke who dances along a touchline to score a try when he's easier to blow into touch, that shouldn't happen."
O'Shea also demanded an immediate reaction from Quins when they face French side Clermont next Sunday.