So my observations after countless PvP Team Battles...
Once one side is down by 5, generally that means they've lost.
Almost every time one team has had that big a lead, even when there's still almost 2 minutes to go... they keep that lead and just keep building on it.
Only once have I seen a team come back from a 5 point trail... and that's cause the other team basically all just went linkdead. LOL!
Good luck on giving up then. You either stay there for two minutes to get your coin(s), or you quit and get nothing. Assuming the observation is actually what happens most of the time, this information really doesn't help you whatsoever.