Another one to add to the statistics. How the hell did that happen? Did the core contact soften before the solder?? Well since the core is off anyhow, I decided to blast the hot air onto the removed heat spreader to see what temperature the solder “runs” (melts) at. Indeed, my source was quite correct, it gets softie at around 80C and at 85C to 90C it starts “running like butter on hot toast”.
Rather convinced that I was close and that I was aiming too centered on the core such that the contacts got softened, I went on to try this on the last LGA CPU I had in my home, a Pentium 4 670. Moving fast, I had the rubber linings cut in a minute, making sure that the rubber lining was cut through all around so I just had to deal with the solder later.