No, I thought Shash would be in his lair from the outset of the fight because when you said you wanted me to post first you mentioned he'd just be 'rolling around in his sleep.' Therefore I didn't have Higan's Electric vision immediately detect the Pater (partially because you hadn't posted so I had no idea where it was) when he did exactly what you mention and span around 360. If there was literally no trace of his enemy Higan would have had to turn back.

I never actually said 180 degree vision was a major weakness, in fact its probably a strength by all accounts, but it's not complete vision. Also, by modern technological standards it's still fairly weak, he could easily have motion sensors or some other exceptional detection equipment. Considering the A.S.P is a scouting vehicle though I decided to just give it really good frontal vision.

Also, in regards to the Pater's ability to fight as an ambush predator, I hardly think that my 'ahem' embellished Computer tracking is really that much of a counter. It allows the Pater to leave false trails or lure Higan, without giving him any distinct impression of where the Pater is in anything less than a given mile or so of forest. If anything you should have been more wary of his Electric vision, definitely more of a threat to the Pater. 

Was its trick actually just the Pater's narcolepsy acting up?