can a full-time employee be told not to come back to work until further notice without being reprimanded or fired and forced to use Leave or go unpaid

A gentleman at my place of employment was sent home on Monday because there was not a ton of work to do. Other employees were then forced to pick up his duties despite the managers insistence that he was not needed. He was sent home Monday, told not to come to work Tuesday or Wednesday, and not until he was called and told to come back to work. He is a full-time employee and did not do anything wrong, is not being suspended or reprimanded. He holds a fair amount of Paid Time Off because he has a son that could need intensive care at any time. Our director mentioned to another employer that he had over 100 hours of PTO (the limit is 500) and she wanted him to use it. She did not require any other employees to go home and actually allowed another employee to go work from home and be paid for it for the rest of the week, and has offered me the same allowance should I feel I need it, yet does not allow this across the board. Is this legal, illegal? Can he fight it?