Let us make it simple. The Corona viris is an obvious biological to weaponize. Thus it was essentailly weaponized. At that point it was taken one step short of been a working weapon. Most likely every level four lab has such samples. For that reason alone, when the Wuhan lab was created, spies would have worked on acquiring an inventory of such samples.
From that point it is as simple as a student doing a private experiment for something to go wrong. So no blame to anyone needs to be assigned.
My main point is that student error and outright slopiness is the highest possible cause of this event. All that also opens the door for DEEP STATE actors as well and that is unfortunately supported by the timing. Recall that the DEEP STATE is embedded in china and here.
Throw in that all the scientists know each other as well.