I'm wondering if they were frozen patties that somebody defrosted in the microwave, but then decided "fuck it" and did a few minutes at high until they were "done"
i bet boiling would look like that too. i wouldnt put any of these possibilities past him but he seems geezer enough that he'd do something absurd like boil-->short grill to make marks
e: wait fuck if they were sous vide that's actually a respectably recommended method. i think internet shaq did a video on it