That being said, you wouldn't have to cheat to get most of the hell gear. I led plenty of non perma groups to satan, I killed every archdevil but Asmodeus and saw all of hell except the court of the pit fiends. Tons of people went on those trips with me, only one or two would have had to log it to have a full path there, then its just getting the people and trying. I might have saw Satan a dozen times, but I failed to see him probably 100. I doubt an imm fed them any info, rather the first 8 circles of hell have been well known to most anyone that went with me during my time (Artificial and Bemused are also both perfectly talented hell leaders that could do pretty much anything I could), all someone had to do was explore the last section of the bottom of hell and get all the real goodies I never got to see.
Shady imm involvement? Doubt it. Do a few of them probably know each other ooc and discord talk? Eh, most likely but CF is never going to have a solution for closed groups that choose to play like that. Do what people did to me when I went and got hell gear. Kill them and sac it and make all those hard earned hours go away :P
Hell was certainly the driving factor when I played. I heard someone finally cleared the place through the grapevine, glad scarabs work got to be seen in its entirety.