As Ty Pilot confirmed, I certainly did not expect to see a problem with flying two typhoon H kits at the same time. I also just ran an experiment using ST-10 controllers and CG03 cameras, both of which I THINK are sufficiently similar to your rigs to be a reasonable comparison. I placed a Chroma with a CGo3 in a chair right beside me, with the WiFi transmitter pointing straight towards me. Using another ST-10+ controller, I launched a Q500 with another Cg03 on board. I put the Q500 out 200ft, then went up 380 ft. There was a little line of sight interference from tree branches, but not much. I started recording on the Chroma that was in the chair. There was no video loss from the Q500. I rotated the Q500 in a complete circle a few times, and it maintained video feed pretty well. Just a couple pauses that are common when I am flying in this area.
I looked on google for the specs of the iLook+. I found the total power consumption, but not the WiFi transmitter power.
Maybe Ty Pilot can speak to WiFi interference, perhaps even in general. My current suspicion is that your friends rig is succumbing to WiFi interference more easily than it should, but, again, I lack the knowledge to really make that statement.
Hopefully someone can join in and make a better statement regarding the possibility that your friends controller/camera may have an issue.