So how does a player recover best from a rush? Anything that can be done to prevent spawn camping like that?
It won't happen often, but it will happen, and if your initial call-ins aren't prepared for it, you'll get raped. Make sure you have enough AT and AI, and in multiple forms, i.e. 1 pak, 1 shrek, 1 hmg, 1 gren LMG or KCH.
Worst case, you can call in forces which are invulnerable if you are forced to retreat.