Okay, yesterday I was in a really close slayer match on boardwalk. There was an enemy waiting down at rocket spawn. The team we were playing was good, so this was a very competitive match. Whoever got rockets would win the game. I met him there prepared for a DMR duel. We dueled it out and I had hit down to no shields, when he jetpacks up to the second level to safety. I would have won the battle if he didn't jetpack away to cover. As I rushed rockets, his teammate popped out from behind me, the jetpacker dropped back down, and I was instantly teamshot. They got rockets and won the match.
It works like armor lock. You can fight someone from the air, drop down to cover, and let a teammate finish them off as you let your shield recharge in safety. I hate it as a loadout. Not to mention it totally ruins all map design/map control.
Horrible implementation in loadouts. Frankie save us.