zlacker

I'd stack the probabilities as following:

1) Bat->Livestock->Human transmission

2) Direct bat->human transmission (your example fits here as a tiny subset, I don't think specifically employees of that one lab are the only people who could have had contact with a bat)

3) Lab leak

I'm rating the probabilities as I see them. Your scenario is possible! It's just not the most probable, and even if it were, there are a lot of possibilities.