You made the correct decision. Your leave was granted on the premise that you would return. When that ceased to be true, you correctly terminated your relationship with the program, ending your medical leave benefit.

As far as burning academic bridges, you'd do a far more effective job of bridge-burning if you flim-flammed your old program into paying for more leave, then told them you wouldn't be returning. Although that sort of information should be confidential, I guarantee you it'd get around unofficially, perhaps not as a statement of the facts, but as, "this si someone you do not need and do not want."

You made the correct decision, and the only ethical decision. Your leave was granted on the premise that you would return. When that ceased to be true, you correctly terminated your relationship with the program, ending your medical leave benefit.

As far as burning academic bridges, you'd do a far more effective job of bridge-burning if you flim-flammed your old program into paying for more leave, then told them you wouldn't be returning. Although that sort of information should be confidential, I guarantee you it'd get around unofficially, perhaps not as a statement of the facts, but as, "this is someone you do not need and do not want."