I would agree - Caffenol, slow stand development.
The oldest film I developed was the roll of TriX that was still in my brother-in-law's Spotmatic when he gave me his kit. The camera had been sitting in the camera bag for more than 20 years, and the bag was deteriorating, so who knows what kind of condition it was stored in. I shot the rest of the roll and stand developed it. Super grainy but discernible images. The pictures that had already been on the roll were lower contrast, for sure.
Tying to find the examples of this. I posted them here a few years ago. Thought they were in Flickr but I must not have tagged them.