The Portugal forward made an angry gesture and walked back to the centre circle with his head bowed after netting the final goal in Real's 5-1 home win over Granada on Saturday, when he also received whistles from sectors of the Bernabeu crowd.
The victory left Real five points clear of Barcelona at the top of the standings, after the champions drew 1-1 at Espanyol.
"He seems fine to me," Real coach Mourinho told reporters on Monday, ahead of their King's Cup last-16 second leg away to Malaga.
"I think it is more relevant that he celebrates the goals that win games and not the fifth goal in the 90th minute.
"I saw him celebrate the other four that were the important ones. If there are going to be criticisms of a player for not celebrating goals, then why not criticise me because I didn't celebrate any of the five goals. I didn't even get up."
Ronaldo, the world's most expensive player, is La Liga's leading scorer with 21 goals, but his performance has been under scrutiny since a poor showing in Real's 3-1 home defeat to Barcelona last month.
There is a perception among some Real fans that Ronaldo can be too selfish at times, and there have been grumblings of discontent directed his way in the last two home games.
Mourinho's assistant coach Aitor Karanka told Saturday's post-match news conference Ronaldo had been "angry with himself because things weren't coming off well for him".
Cup holders Real have a 3-2 advantage ahead of their second leg in Malaga on Tuesday, and they could set up a quarter-final meeting with Barca if their arch-rivals also make good on their 4-0 advantage over Osasuna on Thursday.
