There are times when you are unable to pull agro on the twins in Maw of Lorkhaj

WorldDoneOver

I am unable to load the video taken, from when we were in Maw. There were on several occasions during the start of prayer phase. We would puncture the boss and go home after the room would blow up. Within 10seconds of hitting with puncture; however, the boss will still not agro to the tanks.

lonewolf26

I recommend using the Inner Fire range taunt to trade bosses. Puncturing them during the phase runs the risk that it'll run out mid phase forcing you to range taunt any way. I've had experiences where mixing range and melee taunt on a single boss causes them to go taunt immune if they're traded one after the other after the other. During prayer phase stick close enough to your boss to gain the appropriate aura then Inner Fire just as they're coming out of the prayer. Once they're safely under control on your side stick 'em with your melee taunt. Works like a charm.

Also they're not really doing anything at that phase so no risk of them running wild, and one shotting a dps (except if they're on the wrong side of the room). The only downside is that you'll have a few seconds where their armor debuffs aren't all up but that's a small price to pay for a room under control.

Autolycus

Given what I know from this post alone, it sounds like you are forcing taunt immunity by taunting them too early. Try using ranged taunt once the prayer is almost complete, or just following the explosion.