But he has answered back by saying Owen would NOT have signed for Newcastle without that clause in the contract.
The much-publicised £9.5million buy-out clause was said to be a carrot to dangle for Liverpool, who claimed the striker was only worth that figure. But now Shepherd says the clause only applies until Tuesday.
He obviously could't resist firing a parting shot at the striker, who waited weeks this summer before pledging his future to the Toon.
Shepherd: "Without it, I don't think we would have done the deal - but it is only valid until July 31.
"After that he would have to stay for another year unless it was in the club's interests to let him go.
"I think he owes Newcastle quite a lot, I'll put it as bluntly as that. I think he's played more times for England than he has for Newcastle, so I think he owes the supporters quite a lot."
Owen has played only 13 games for the club since joining for £17million from Real Madrid and Shepherd told Liverpool fans (recorded on a camera phone video clip which later surfaced on the internet site U-Tube) that he would "carry him back" to Anfield.