It's not just the administration, in my view.
A few years ago (maybe 7), at the start of TT week, just before the roads closed I was in stationary traffic, 10 yards away from a police officer. A motorbike crashed into the back of me, he was taken to hospital with leg injuries (he recovered quite well I understand) and fortunately he was discharged a number of days later- his bike was a "write-off" (I think). My daughter was in the car at the time (aged about 9), and the Police were superb with the way they moved her away from the situation whilst it was dealt with and they spoke to me.
I was, quite rightly, breathalysed, which was negative, and then the officer commenced to complete a "notice of intention to prosecute" despite the fact that he had seen what had happened with his eyes. He was eventually dissuaded from doing this, and I was given a "producer notice" to produce my documents. This I did, in the requisite time.
The guy who ran into the back of me was given, by concession, longer to produce his documents. Unfortunately by the time he was required to produce the documents, he had left the Island it transpired that he wasn't insured. Had he been required to produce the documents on the same timescale as me he would have still been on the Island at the time, with an opportunity to take him before the courts, I don't think that the matter was followed up by the police.
Maybe things would be different now, I don't know - but it felt to me that I was being treated more harshly then a visitor, who (it appeared) "escaped" without penalty.
Of course it must be difficult for traffic officers to deal with matters during TT, and I have sympathy with them - but I think that the way that "special treatment" was afforded to a visiting biker/motorist represented a tacit acceptance that visitors weren't being held to the same high requirements as residents, with the consequential impact on road safety and behavior.