I'm not an investigator and I don't have their facts or finding, so this is all just an extremely uninformed opinion.

I absolutely think a leak is plausible. But if 96% really is the similarity to the closest lab strain, then I just wanted to put in context how dissimilar that is genetically. I think it's one of those times where 96% sounds really high, but genetically it's pretty divergent imo.

It's still totally possible that it's a leaked strain and maybe the lab just destroyed the records of that strain or something. But taken on its own, 96% isn't that high in this context.