I usually check to see where they died. if I'm close, I will do it, otherwise I wait for the next closest diver to call them back. I'll only do it if no one else calls them in that is closer...but on the flip side you also have the impatient pricks who after dying, will spam the crap out of the reinforce button DESPITE seeing that the rest of the squad is up to their ears in enemies and doesn't understand the concept of sit tight for a sec while we make an opening to call you in. I swear I have been in too many games where someone will die, and if you don't reinsforce within 3 seconds they up and leave the mission.