We need faction lock in Dungeons!

Today I have queued for random normal as a healer. But when I entered Fungal Grotto I... I don't know how to say it. There were two DDs from another alliance!
And they wanted me to heal them!
They kept dying.
I took the oath the hypocrates so I had to heal them.
I had to do it!
And they laughed when I did it.
Because they knew I am bound to heal them even though we were enemies.

Now I feel so dirty, so used. Have I betrayed my country?
I have, have I?


Please do something about it! Put faction locks in Dungeon Finder.