Okay, there's apparently something along the lines of a scry on here at all times, but not enough like a scry for his Mind Blank to beat it, that's a problem, let's see how big of one it is.
It's possible that there's at most one more guy he has to control in order to erase any records of him being here, if that's true he can just do that as a stopgap until he orients to just what's possible here.
Probably it's not that easy, in which case he can't actually pull off not leaving a trace behind and should just kidnap Smasher and let them try to look for his current face, which he'll just never use again.
Either way it's not worth keeping up the illusion that he's able to lie just to make interrogating him more convenient, if it means these "cameras" will pick up more of what he's doing.
(This is the sort of thinking you can do in ten seconds, at Int 26)
"How many people would I have to control in order to get all the records from when I showed up and on erased?"