Since it's not your land it's not your call ,
the "other guy" has permission to be there and apparently your father in law sees nothing wrong with his choice of stand placement . Stirring him up the way you did also doesn't help . This is the same type of situation that you might face on public land , either learn to share the woods or hunt somewhere else .

BTW , did it even cross your mind that any deer that will circle around him are probably gonna pass right by you instead ?