So.... what are the chances of an insurance investigator, who by the nature of the beast are paid to find a way to avoid liability... not stumbling into this?
Now they will be looking at any claims in the system for a group operated plane and they will dig in places that "your friend" can't possibly falsify.
ATC records are kept for a while and the AAIB can ask awkward questions, and probably will, if the insurers find a hint of wrongdoing.
Have your friend ready to answer questions like, why is every take off and landing not supported by documents from the airfields concerned? payment of landing charges and records of take off and landing times might be hard to fake.
Where did he go on the flights in question, and why is there no en route ATC or FIS recording?
Do the engine and airframe service records support any "additional flights" that are claimed? If they do encroach on service intervals, do the records of the maintenance provider, if used, support this?
Is the pilot employed? Was he at work on the days he claims to have been flying... was the wx suitable... do fuel receipts support the extra use? All of that can be traced, and they only need to find one "error" to give them enough cause to dig deeper.
If the aircraft was not flown enough in the previous 90 days, then you need to invent flights, but if you claim flights that someone else did, in order to be "more current" then you are at risk of being exposed when the investigator asks to see the log books of all the other group members.
Are you all confident that you are all going to lie to the insurers and AAIB?
Even faced with a suggestion that "if we don't lie" they will not pay and we lose the aircraft and possibly have third party costs to meet, are you really sure that the innocent will lie to entangle themselves in your friend's plot?
I suspect that I'm not the only person who would like to know more... like did your friend submit the altered report yet?
Did the request to alter the report come by some means with evidence, like email?
What pprune id did Steve1234 use before this issue came up?