Yea. He's wearing the shirt for the purpose of provoking people with it. Listen, if he had just been a random dude who had that shirt and decided to go to the mall that day I'd be more in his side. But he's not. He was told multiple times on other days, to leave for preaching both inside and outside the mall.
Or look at it this way. If I were to wear a shirt with a picture of a Christian cross, crossed out, that said "Islam is the ONLY way" to a mall in the deep south, after being told to leave for preaching there multiple times, you think I'd catch some shit for it after enough people complained to management?