The turret’s laser can go through walls:
[2104.93] Log: Log file open, 04/29/13 00:47:41
[2104.93] Log: Dumping BugIt data chart at 2013.04.29-00.47.41 using build 8710 built from changelist 19039
[2104.93] Log: MapName: OBJ_Camden
[2104.93] Log: Description:
[2104.93] Log: BugItGo -1333.1943 2396.2415 3056.1499 -3828 3852 0
[2104.93] Log: ?BugLoc=-1333.19,2396.24,3056.15?BugRot=-3828,3852,0
[2104.93] Log: ---=== GameSpecificData ===---
[2104.93] Log: Log file closed, 04/29/13 00:47:41
Also, when you knock over the turret, it goes through walls. Throw down a grenade next to a turret and watch it fly through walls. Also, it varies per person when the turret goes after it gets knocked over. I saw it right in front of me when someone else saw it 10 meters away.