The OP poses the question of whether human pity could ever possibly be against the will of God in His judgment. The answer from the Bible is YES, on occasion.
Now someone tell me what was the act that caused God to take the kingship AWAY from King Saul and deliver it to David.
What act did Saul do which caused God to reject him from being king over Israel, replacing him with David?
Hint: Read First Samuel chapter 15.