According to Aaron Greenspan in his recent lawsuit "a vast sum, if not the majority, of Dwolla’s transaction volume is the result of Bitcoin speculation."
So it should be interesting to see what impact this has on Dwolla's business.
Wouldn't it be the responsibility of Mt.Gox and Dwolla to submit the required forms? Unless you are saying you think having money in Mt.Gox qualifies as a foreign account and he should have filed an FBAR.
I'm not a financial expert by any means but it's pretty clear when you're moving cash to Mt. Gox, you're moving it out of the country. And I think the paperwork is a joint responsibility.
If they do ACH, it's never really settled, it just hasn't returned yet. Some classes of returns are limited to 3 days, some 60, and some can be clawed back a year later.
Their proprietary exchange might have different rules, but iirc, it's not very widely distributed yet.
The main impact will be on their gross processing volume, which is in some respects a vanity metric because of their pricing model. Revenue will be impacted, but as your example illustrates, not directly or proportionately.
So it should be interesting to see what impact this has on Dwolla's business.