I think Jesus was angry because the man disbelieved Jesus’s humility, not thru Jesus’s fault but probably because Jesus’s disciples may have wanted to guard Jesus against leprosy. In other words, the disciples may have tried to bar the man’s way, leaving him to think that Jesus himself did not want to heal him. Jesus’s entire ministry revolved around personal humility, placing others before oneself. It made him angry that his message was misconstrued.