Evo - vs. Vanessa... how to escape the punches?

This has become a major subject of discussion amongst my VF crew... promised them I'd find an answer. Please help.

When Vanessa lunges and straddles you, the defense for her + is a natural response to throw escape and that's great... but none of us know how to foil her from that position.

Thing is, various members of our tribe seem to pull it off from time to time... but no matter how instant and intense our interrogation upon witnessing a successful escape from V's brutality, the person invariably shrugs and says "I'm not sure what I did". I've tried reversing it (wouldn't that be a low punch? +) and throw countering, but I can't figure it out.

The one guy (he's pretty new, but shows promise) who does it most reliably tells me "I think I hit down and punch", and I just want to scream "that doesn't even make sense!!!"... but I hold it.

What are we not understanding? Especia Especially, lly, if this is a global technique, as I suspect it is (I think there are some other situations where escaping is possible but mystifying to us so far), it could really advance my group's 'game'. Someday we'll kill you all, I swear.