Hi Wartwo,
I believe this was a bug. By my count you destroyed the same four allied fighters three times!!
The event of note in your PBEM is that your planes targeted the cruisers. In five single player trials the Imperial planes targeted Pearl and then in the next turn went after battleship row as usual.
I tried to replicate the bug in single player mode but couldn't. I got cute and tried to reinforce Pearl with more aircraft before the Japanese strike but only got the same 4 fighters flying cap--all of which were quickly killed and stayed dead. I tried calling in aircraft reinforcements while leaving the Enterprise and the separate task force of 2 cruisers patrolling but still got my butt kicked.
I don't think your opponent was intentionally trying an exploit. His cruisers were disengaging as appropriate. Can you find out what his aggressiveness settings were?
I've found the aggressiveness settings a bit touchy in my games, but I think the problem was with your opponent's zombie fighters coming back from the dead!
(I'll leave further comments to the game's developer)
Best, -Charleston
p.s., I'm looking for more PBEM opponents, let me know if you're interested.