"Destroy a ship at full health during a single cloak in the Stealth Cruiser."
Using a 'Stealth Cruiser', full hull integrity at the end of the battle, just killed a ship in 2 rounds of lasers and beams, while the stealth was activated once.
Still didn't got the 'Birds of pray' achievement, what did I miss?
Reading the Wiki - Bird of Prey, it does say that:
'the ship must remain cloaked from the start of the volley until the battle is over and the after-battle text pops up.'
I think the reason is that the ship just didn't last until the text and the cloak was done just before it :-(, well at least the mystery is solved.