Navy F4F vs Zero

[CJE]

According to many sources, the first Navy F4F pilot to have shot down a Zero is Ens. W.A. Haas of VF-42, on May 7th - first day of the Coral Sea battle.
But...
According to Frank Olynyk's lists, he claimed two "VF Type 96s".
The only credits for Zero kills are for AR3C John Liska (two!), rear gunner of Ens. J.A. Leppla, who claimed a third one. The crew belonged to VS-2.

Japanese sources mention that "Shôhô" put into the air 4 A6Ms and 2 A5Ms. Three were lost (thus, there is at least one Zero), the others making an emergency landing on Deboyne Island.

In the late afternoon of same day, VF-2 and VF-42 claimed 4 Zeros. Lt.Cdr. P.H. Ramsey got the first "official" credit for a Zero.
But Japanese sources mention that no Zero took part in this mission over the US fleet because it implied a night landing and the Zeros had no blind flying equipment.

It leaves us with the first air-to-air encounter in mid-day of May 8th.
Though on top of Frank's list for a claim vs a Zero, Lt(jg) E.S. McCuskey states in his combat report that he first saw his wingman (Lt(jg) W.S. Woollen - both of VF-42) shoot down a Zero before he claimed his own.

So, I assume that Woollen is the first Navy F4F pilot to have actually shot down a Zero.
What do you think?
Thanks.
Chris