Of course. As Catholic I do not obey laws that are injust, expect persecution for my beliefs, and defend the Church from slander regardless of what the authority might do to me.
Do you believe the government should jail someone for making this statement?
Yes, slander is a violation of natural law and therefore the governemnt should punish the slanderers.
I do not condone the specific situation in that parish, especially forced participation in festivals. Cops acting like thugs in Mexico? Stop the presses.
However, the jerk calling people idolaters who reject the gospel is a catechist. First, he should know his own faith better, and if there is an unhealthy slant in these celebrations, he should have alerted his bishop, rather than bolt to a Protestant sect. I do not recommend doing what allegedly someone did to him, -- if they did, -- but I do not see anything admirable in his actions, and so the reaction is predictable.