Those numbers included penalties in penalty shootouts. Perhaps Ronaldo chokes a little on penalties in big moments, since a disproportionate number of his misses seem to have been in important moments. Meanwhile, tons of Messi's missed penalties are in CdR matches. But it's not like Ronaldo hasn't made plenty of important ones or that Messi hasn't missed some important ones too.
Remember, Messi missed one in a very tight CdR quarterfinal tie in 2008. Barcelona still won by one goal, but it was an big moment. He missed one in a 0-0 La Liga match against Sevilla in the 2011-2012 season. He had the Chelsea miss, which obviously lost the tie for us (and I think Ronaldo's teams still won all the CL matches/ties where he missed penalties). He missed in the 2013 Spanish Super Cup, which we would have won if he had made the penalty. His miss in the CdR first leg this year against Atletico was big, even though we ultimately ended up winning somewhat comfortably. Taking only a 1-0 lead to the Calderon was not exactly safe. The miss in the first leg against Man City was perhaps less dire, since we were taking a lead to the Camp Nou regardless, but it was still relatively important.
I'm not saying all that to disparage Messi. He takes lots of important penalties. Of course he has missed some of those. But the same is true of Ronaldo.
