Senior PvP Designer Brian Holinka tweeted just a short while ago about the temporary removal of one of patch 5.3's shiny new systems: the one that balances healer numbers in opposing random battleground teams.
@phxtich We had to disable the healer balance system as it had a bug that only revealed itself with live numbers of users.- Holinka (@holinka) May 22, 2013
As a result, the system has now been temporarily disabled. This means that teams with unequal healer numbers will reappear, so don't be surprised that the system is not working. Bugs do happen, and as I'm always going on about, PvP is a rare thing on the PTR. So it's no surprise that, when big new features like this go live, they might not withstand the strain. If you want to stop these problems, don't QQ, get on the next PTR and make with the stabby. You'll be doing yourself a favor! And while you're waiting, WoW Insider has a guide on helping the healers you do have in random battlegrounds.