Yes. If he conveys 100% of his interest in the property to you, you do not owe anything to the lender. He does. Therefore, YOU have no debt to refinance. HE does. But, he doesn't own the property any longer. He can't refinance and pledge collateral that he does not own. Chances are, there is a due on sale clause which means the note will be due once the lender is made aware of the sale. And if he conveys interest, it IS a sale.
If you are 50% owner, the lender could still exercise their rights with the due on sale clause. In this scenario, you might be able to refinance as a co-mortgagor with your soon to be former friend. If you think there might be a mess owning a property with a friend, just wait until you are jointly indebted on it.
Sport, these people are trying to give you very sound advice. This is a bad idea.