Originally posted by arnold IHe suggested the film could have suffered heat or radiation in transport (before he sold it to me).
I used ASA 400 as a reference setting He scanned JPEG for me and below is the original, along with another unaltered example.
Definitely NOT heat or radiation. If the lab said that, they're either ignorant (not good) or they're covering their tracks (not good).
Film that is heat damaged would, if anything, have lower contrast. Radiation in transport (aka X-ray damage) would only affect parts of the image, almost like a light leak.
Ilford XP2 Super has a huge exposure latitude and dynamic range, so even if your light meter was off, 400 ISO is the default recommendation.
My best guess based on what you've shared is that it's a combination of causes.
a) Over development of the film
and
b) Scanning profile is set for too high contrast.
Are there alternative labs that can develop your film and scan it? If you have access to photo editing software, ask the lab if they can scan it to TIFF or DNG and not jpeg.