u/Swimming-Pirate-2458

Hi, I recently bought a laptop off my old employer after I left the company. During the process, the battery died and the pin screen reset to a 50 years lock meaning I couldn't enter the pin code. I hooked it up to an ethernet, entered the pin they gave me, and then i clicked Macintosh HD and it let me create a new profile.

But im worried about if they still have access at all, is there any way to check if they can do anything to it? They did give me instructions, but because of the locked pin, the recovery was different to what their instructions were and now I'm not sure if they can still recover it or something