It'll have been a glazier, sub-contracted to whichever firm managed to underbid the rest for the council's housing maintainence contract.
In Portsmouth, we're talking £12M+ a year (in reality it's double that, as explained below) where the works policy is solely to make good. This means the cheapest, least labour-intensive solution, per visit.
The front door on our old place was a low budget, solid wood type from the 70's. It was rotting from weather invasion and took 6 visits over 18 months, scarfing the rotten wood out of the frame and replacing the door itself with similar on three occasions - cost each time was approximately £400, and £700 to replace the door.
When they'd finally scarfed out so much of the rotten frame it needed a complete unit replacement, they finally agreed to install a £1200 PVCu unit (extra wide for my chair, with flush weather bar).
We were not allowed to just replace the door ourselves (at our expense).
It's ridiculous that the contracting firm are allowed to bill nearly £7000, to do what any competent private firm would have charged £1200 for (fitting the PVCu Unit first time round), but that's the nature of council contract tenders.
My wife's best friend is the lead surveyor for our local authority's contractor and he is appalled at just how much added expense is incurred by doing the bare minimum to fix the issue, rather than the proper job to prevent further costs (but he does enjoy the Maserati it pays for).