As much as I love new pacifist ways of winning battles, I think this is a bug. The code that checks if your party is using too many tokens should also verify that your party contains at least one char. I'm pretty sure this code is already being used in MP, so applying it to SP should be easy.
Good news, it doesn't work anymore! It did seem rather exploitable, as by using only the pass button you could use a macro to pass repeatedly along with max animation speed, and get huge amounts of loot depending on the internet speed, so good thing it was found before anyone could abuse it. I'm guessing this is what the server downtime was for?
hmm. Must have been fixed before now, then. I did discover it a while ago, but only bothered to post about it recently and didn't test it before posting. False alarm, I suppose!