I can't believe I have to cut and paste definitions from the dictionary, but this is what escrow means.
es·crow
n. Money, property, a deed, or a bond put into the custody of a third party for delivery to a grantee only after the fulfillment of the conditions specified.
The $300K was placed in escrow as a NON-REFUNDABLE deposit to secure the stock purchase agreement. In the event the stock purchase agreement did not happen, it was to be released to the registrant, which is PGRD.