This man maintained that he himself was the truth. The priests claim they have the truth. My Roman masters claim their way is the true way. It is pretty clear that the truth is whatever some group claims it to be, or whatever some person can convince some group that it is.
What is the truth? There is no truth. There is just existence, and our groping our way through it until we, like this man, cease to exist. He thought he was the truth, with a capital T, like so many other demagogues, some benign, some murderous. Anyone so convinced of their own rightness can't be trusted with real power, and this man was becoming powerful, at least with the mob.
It's a bad end. But what else could have happened? This man fell afoul of the restoring forces that maintain stability in societies. That's all.