It's already fixed as I mentioned before, but let me explain again what happened.
(numbers are approximated)
the matching engine receives a 30 day market bid of 10k. (there might be a chance this bug occured for x-day bids (x!=30) where 30 day offers are taken)
The loan offer book, filtered by period=30daysormore looks like:
14k$ @ 0.14%
>100k$ @ different percentages between 0.141 and 0.5%
20k$ @ 0.5%
Normally the engine will match 10k$ at 0.14%. But the public lending history log showed 10k$ @0.5%.
My 30 day loan offer @0.2xx% was still sitting there!
So I cancelled this offer, offered at @0.5 and it got matched within no time.
Some time shortly after, I saw matches @0.75 and got some matches myself with some money that was released from other loans.
During all of this time, there existed 30 day offers at way lower rates. (e.g the 14k offer was still sitting there according to the bfx book and bfxdata.com book (which uses the public api).
I got a nice 7x interest compared to yesterday

But it is clear from your description that you obviously weren't the only one who had noticed or in fact been using this flaw. Heck, I guess all these dudes will be very angry at you now when you have reported it to the support team (provided the bug is really fixed, of course). The only thing which I can't understand is why anyone would take loans at so high an interest (like 0.75 per day) when they could easily borrow at much better (i.e. lower) rates?