It's a glitch, most probably. Don't worry, your stats are just as fine, it usually happens like that because of lag and especially in Player Ranked servers.

Or it could be that the server you were in was flagged for stat padding. If that's the case then they took away your points and you will not be getting them back.

I don't think Save Games are able to be swapped in Warhawk, ,mainly because, stats are tracked by your PSN name, not with your Save, otherwise, there would be TONS of Generals, from people using a posted General Save. Also, Like delta and Louie have stated, you could have either been experiencing the Stat Glitch or could have been on a server that was reported as Stat Padding.

Yes same thing happend to me. I'm a 1st Lt. and i went back to reqrute. after about 5 seconds it changed back. Its either your connection or the warhawk people have wiped your stats for cheating. As long as you don't glitch or cheat in ranked servers you should be ok.