4 days? November? Was this aircraft towed in and out of the hangar with a techie sat in the seat on brakes !
The seat pins should have been moved to 'Safe for Maintenance' position and signed/countersigned by the armourers . . . 4 days later when towed out, they should have been placed 'Safe for Parking . . .
"Should have" - oh those awful hindsight words. "I should have" " He should have" In the end it's always the same.
I/he/she/it didn't.
During my time in the Royal Air Force I always,
always,
always checked the seat pins carefully before getting into the seat. One day I was lying on my back under a Vulcan instrument panel working on a pitot-static fault. My legs were resting on the seat and my tool roll was on the seat between my knees. I was reaching for a spanner when I noticed that the seat pan handle safety pin wasn't there. It wasn't on the floor near me, so I hadn't dislodged it when I worked my way in there. A while later someone came along and I asked them to put the pin in and yes, there it was, stuck in the stowage on the bulkhead behind the seat.
Complacency is something that creeps up on you and complacency is the root cause of so many accidents.
I learned about Maintenance from that . . .