I think you pegged it. My guess is that the lender required the developer to pre-sell a certain percentage, and now that the market has softened, some of purchase contracts aren't looking too good.
So he went out and got several wealthy investors in town to "buy" a bunch of units up front, with the understanding that they'd be bought back once the financing package was finalized.
I'm thinking of putting in a bid on one of these units for about 50% of the listed prices.