Honestly it matters little if it wasn't as simple as an off-by-one. Crap happens. If this was their ultimate failsafe, it's an extremely bad failsafe from a client perspective. Sure, the servers didn't crash, that's the good part. The game is up and running. That's step 1.

But your clients need information. The players should have received different information than '0 won, please take your money back.' Any instance of a failure to process or a bad or null value being returned should have been trackable. And the fact that they're showing 0 here means that they are, at the very least, trackable after the fact. Something should have been done with that data to ease the players' minds.

If you don't interface with your clients directly as a programmer it's easy to lose sight of giving them pertinent information. That interfacing is hard to have in big companies. More concerned with keeping the system running, absolutely, but they still need information. If a better error message was displayed people would be less rambunctious and they'd know what their next steps would be, even if it's "Wait, because SE is investigating what happened." People feel they've been screwed - forced now to enter a lottery on a smaller number of houses that will have more people competing for them, and you can't blame them for feeling this way. Clients were presented with a big unknown today, and their time and in-game money is on the line for it.

To me it says the developers of this system didn't ultimately think there was any way they could get to this logic state, so as long as it didn't break the servers, fine fine.
Whoops, instead we have a massive amount in this state and confused/upset players.

And now it's on SE's PR to immediately get information to players as soon as they can figure out what can be done, especially considering some players have already taken their gil back from those bids which further complicates everything.