The start button did make contact and register since it beeped when pressed while the error mode was present. It had no other effect other than beeping while the error mode was present. The error mode occurred without any interaction from the start/pause button in the first place, so it would seem unlikely the button would fail after an unrelated error. After the error was cleared by unplugging the machine, the start/pause button continues to work normally. When I entered the room, it probably was 30 minutes or more since the error occurred, so waiting longer should not really matter.
From everything I've learned, it seems that the machine entered an unknown or unusual error condition not normally encountered (once, maybe twice, in 2 years of 4 wash loads average per week - we really like the machine.
I'll treat it the same as having to reboot my Windows computer now and then to fix a problem no one will ever find at any price - and I write software for a living :)