The judge can rule that freedom of speech is not at issue. There are many well-settled instances in American case law where one's right to freedom of speech may be constrained (usually because it conflicts with the rights of others).

E.g. in this case the accusation is that Olson vandalized BoA for 6 months, causing the bank to have to continually pay to have the chalk cleaned off and risking further property damage.

Olson has a free speech right to protest, but that does not mean that he can unilaterally choose means that infringe on the rights of others.

You are right that foreclosing the issue may make great grounds for an appeal though, it's possible an appeal court could rule that the First Amendment is relevant and cause the case to be re-tried.