A lot of the digital cruise controls that I've used in cars increment by 1 for each press, but increment by jumps (3-5 IME) if you hold it down. I wonder if that bug is a state machine problem. Pressing fast enough puts it into the "holding" mode, but because you're not actually holding, it also doesn't register that you've "stopped" holding.

Nope, it only affected that one position. Like in the previous example it would go 104->105->107->108.