Employee isn’t returning after disability leave: What can we do?

Q: "We have an employee out on Short Term Disability since July 21. His doctor's note said to come back to work on Sept. 13, according to the disability insurance company. The employee is still out and he says his doctor still wants him out. But we have no proof of this and neither does the insurance company. We know the doctor doesn't want him to come back with his disability (pacemaker @ age 42). His job requires a lot of above-the-head work and lifting, as well as snow shoveling in the winter (he’s a painter and maintenance man). What are our options? Terminate? Will he be able to receive unemployment? If so, is unemployment based on the disability pay or his normal pay?" -- Michelle, New York