re: Is Jester a coward for diving below the hard deck during that first dogfight?

Technically, the hard deck is established to simulate ground level, but also to try to prevent defensive maneuvers that might result in loss of control episodes that might result in unsuccessful ejection attempts. Most tactical military aircraft OOC/Spin Recovery procedures that I'm familiar with call for mandatory ejection if recovery is not established by 10,000' AGL.

So not only is it a training objective to pimp you that you're reaching ground level, it's also designed to keep you from attacking defensive people in an envelope that could cause an extreme reaction and maybe lose a jet.

So real world training, Jester should have acknowledged his bust, rocked his wings and kill removed. Mav/Goose should have leveled off at 10,100' and pumped another Sidewinder into him for good measure.

So was he a coward?

Not necessarily. I morted myself on the rocks many times. But you have to acknowledge that you lost.

Coward? No
Bitch? Maybe