The vampire will not be successful in defending himself. They may put him in one of the crates for someone else to find him. Since they're wearing masks and the vampire is fairly intoxicated, he will have very little memory of what happened.

They'll be able to return to their search. If Geralt follows his nose, he will find a leather sachet. This will be the second one found. The first is being investigated here.

They may take it and leave, and continue to investigate the second sachet itself here.