Does charmed pet (or any pet) need to be behind target to backstab?

[TripSin]

I'm more concerned about charmed pet because I don't think enchanter pet can backstab, right?

Had a group member say that the pet needs to be behind the target to get backstabs and whatnot. But I feel like I had been charming a rogue in highpass hold that seemed to be doing backstabs even when it wasn't behind the enemy it was attacking. Anyone know if positioning matters for this?

Thanks in advance.