My first jet course was in the mid 60's. I've spent the rest of the time thinking a plug fit was a door that is pushed outward by pressure and plugs the hole. i.e., the BAC 1-11 had a front door with lugs and a g lock, while the back door was a plug fit. (the back door went to a ventral staircase through the pressure bulkhead.)
For what it's worth, I think the bolts were not fitted. However, the point I raised about the safety bolt being near to the end of the roller pin still nags. The end edge of that pin would make a modest but real cutting tool if it were playing on the curved side of the bolt. Having said this, I'd imagine just about all taxiing would be done with the aircraft pressurised and pad friction stopping relative movement. I can't imagine any other force jarring the door sufficiently vertically.