I guess it's technically possible a malfunctioning machine could output literally any string of bits.
The chances they would just so happen to look exactly how a particular emulator wrongly displays them, and do so over and over, is virtually zero.
The chances they would just so happen to look exactly how a particular emulator wrongly displays them, and do so over and over, is virtually zero.
TL;DR MAME would have to emulate a CRT's electron beam drawing in the original cabinet's direction if it wanted to be spatiotemporally identical. The notion that a cabinet could glitch out and accidentally perfectly emulate MAME beggars belief.
Like you said, I suppose it could happen, in the sense that it wouldn't violate the known laws of physics.
But it didn't.