I had a mental block about this for some time and will spell it out for anyone who is similarly confused. The idea is that if you pass the deadline for returning excess deferrals, you leave them in, and whenever they are taken out (termination of employment, retirement, etc., maybe many years later) they are taxed just like any other plan asset. But "taxable in the year of deferral" means that the participant doesn't get a deduction. So in this case the returns are amended to show higher income, and that's about it.
Mike is pointing out that when they come out, they are/should be just a regular distribution, with regular coding (1 or 7 or whatever). It's too late for a corrective distribution. If the "regular" distribution wasn't allowed, then that creates a different problem.
FWIW and hoping that the freeing of the mental block was in fact accurate...