It would prove that is can be a random trait. You're right!
But IMO it is not completely random. This year I'll produce 20-30 het pied eggs and I'll wager that 90%+ will have the marker... so far I'm at 100% with the maker.
The real question is how good an indicator is the marker when you're dealing with possible het pieds. I definitely don't think that every non-markered poss. het is a normal.
Justin