Unearthed glitch

So I just got the new map pack and started checking out the maps. But when I got to Unearthed and played an easy firefight match, I started as an elite, but had spartan lives and the covenant wouldn’t attack me unless I killed a couple of them, but they were still my allies until I attacked them, then after a while they would become enemies and then allies again. I searched all over the map and there were no Spartans anywhere and I was playing by myself. I was online but I was playing a local firefight map with just myself. I ended the game to see if this would happen again and to check my setting and everything was standard firefight. Then I played another game of firefight and everything was normal. Anyone else experience this, heres a video so you can see.

Youtube uploading
the video is also on my file share http://www.bungie.net/Stats/Reach/FileDetails.aspx?fid=15183331&player=Ou7of7ime

That’s not a glitch, you simply switched to the Blue Team ( The Covenant Team in Firefight ).