My guess is they both have taken money they weren't supposed to. I tend to think Kate is squirreling what she took away though and Jon has been spending it. The quicker they get divorced the quicker they each get their own money.
The thing I don't understand is, when Jon moved out, was there any determination of how he was supposed to pay his living expenses by the arbitrator? I mean if the arbitrator said he couldn't take any money out of the accounts, you would think he would have given Jon an allowance or something? Or were Jon's bills just going to Kate and she was paying them? I find it hard to believe TLC was paying the full rent on Jon's NYC pad, but if they were, who is paying that now? It's 2 bedrooms/2 baths, the rent must be a fortune.
I thought they both live at the house in PA they have 50/50 custody at this point. Jon just rented a place in NYC for Kates days. Kate has to leave too we just do not know where she goes. Kate must have bill too that need to be paid.