This is unfortunate,
Due to violating the following rules and because they have already accepted money and started the domain delivery, the seller is receiving an unacceptable business infraction.
6.2.3. An auction cannot be modified once a bid is placed with the exceptions of its Buy-It-Now ("BIN") price (e.g., a BIN price may be added), its bid increments, approving additional bidders, adding payment methods, and/or adding additional domains at no extra cost.
Once a bid is placed, every allowable change (the exceptions just mentioned) must be posted to the thread as a new reply as well as updated in the original post before it becomes effective and valid (e.g., a BIN price cannot be accepted until that is done, but rule 6.2.10 applies). BIN prices are not reserve prices and therefore do not affect
rule 6.2.10.
6.2.4. A Buy-It-Now ("BIN") price may be changed (added, reduced, increased, or removed) on an auction prior to it being accepted, in accordance with
rule 6.2.3.
The BIN price in an auction must be publicly accepted by a buyer.
As outlined in the rule above, the seller failed to update the auction with new post in the listing with the new BIN price so that all bidders were given a fair opportunity to claim the domain at the BIN.
All BIDs/BINs MUST be made publicly and transparently. You may not sell a domain outside an auction once bids have been placed.
The SOLD at BIN post was not valid since the seller never made a new updated BIN post in the listing to alert all the bidders of the change to the BIN Terms.
An unacceptable business infraction is now being issued to the seller for failing to be transparent in their auction and selling the domain outside the auction in a direct message.
Sorry it didn't work out.