What part of the statement are you interpreting as Cruz siding with the protesters?
All of it, the tepid intro is merely cover for what is know as a “Yes but”, defense.
Cruz is saying
Yes what was done was wrong BUT it is justified because..
Anyone NOT welded at the hip to a candidate hears it that way.
“When the candidate urges supporters to engage in physical violence, to punch people in the face, the predictable consequence of that is that it escalates,” Cruz said. “Today is unlikely to be the last such incidence.”
Saying "I'd like to punch him in the face" is NOT the same as exhorting your followers to do the same.