The simple fact is Ronaldo is a winger, played the vast majority of the year on the wing, and outscored a striker, thats entirely no mean feat. He was also 80% of the teams driving force from midfield to attack so even when he doesn't get the assist half the attacks have him to thank. Higuain is good, but not as good as Ronaldo, though it would be interesting to know who scored against who.
Ronaldo was getting used to a new club and new league, Higuain wasn't. Also Ronaldo definately doesn't take all the freekicks and penalties. He handed off several to Kaka at the very least, and Diarra, Alonso, Kaka, Marcelo and Ramos all take freekicks, Ronaldo takes more than most though, and he'll score more than anyone else taking freekicks so not sure how thats bad, its part of his game.
If he'd taken all the penalties he'd have another 4-5 goals on top of what he has.
27 goals for a striker is very good, but its not flat out fantastic, 26 goals in the league for a winger, is pretty much astonishing.
As seemingly shown, with a decent winger instead of Kaka, and without playing with Benzema who is useless and after a year to get used to the league/players, his strike record is significantly improve so far, 8 games, 10 goals, 4 assists, Higuain is on half the goals so far.
Yes that includes a ridiculous 4 goals in one game, but Ronaldo is someone you would bet on doing similar all season.