if that postdoc does not do his work, he is cheating the

money from NIH and the institute. Only 4 months left, it does not worth the efforts to let him ago. If more time left, like >6 months, I would strong suggest to take actions to let him go. He is wasting the PI's time, wasting the money from NIH and institute, and ultimately wasting the tax money from tax payers like us.