Thats news to me! Very rarely have I heard of Easterns being problematic feeders. Their ferocious appetite is second only to the mighty Mexican Black.
In my experience, Grey Bands tend to be the worst to get started on f/t rodents but seeing as your Eastern is wild caught, this is probably why it is refusing prey items, namely stress. Personally I would set it free and let nature take it's course but obviously it's your shout.
Good Luck
Fergie