PvP, disconnects & lockout

So i did random matches with 2 friends when suddenly our Tank disconnected just as we go served by the other group.the match ended with our Tank having disconnected but still alive and the rest of our group dead.

when he returned we couldn't re-enter and he told me he was locked out for 30 minutes.
just earlier i had disconnected during a match twice aswell but made it back before it ended and everything was fine.

so, what's the deal?
is this something like a penalty?
i guess i can live with this if SE ahd fixed their random 90k errors, but untill then, i prefer them to not have a system like this in place.