If you believe the contract implicitly allocates that risk to Patrick, then equitable mistake wouldn't apply.
Patrick
explicitly allocated the risk to himself. Thus, equitable mistake doesn't apply.
I know there are some risks involved and potential to lose serious money on some of the loans I have out in the wild.
I... carry the risk from bad loans and the timing of requests.
This is explained a few posts up:
https://bitcointalk.org/index.php?topic=61262.msg1291861#msg1291861As coinft points out, if the loans had done better than expected the excess profits wouldn't have been equitably split, they would have gone to Patrick.