Yeah, nah. You're conflating certainty with risk.

Crazy virus comes from where said crazy viruses are literally made and studied.

Occams Razor suggests a lot, but more importantly, smart risk management dictates that you treat the lab as if it is the source; absent some sort of clear risk-related reason that these experiments are likely to do more good than harm.

So I suppose the correct question is -- what are we getting from these labs that's worth the risk of leaks?