I've often thought about how easy it would be for that to happen. You really have to press down on the quick disconnect to get it seated well before pushing the lever down. If it's not leaking, it should be fine. I broke the quick disconnect on my eheim about a year ago, it's been fine since.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry