None. It is not a perfect criminal defense to having committed a crime that someone else asked, threatened, or incited you to do it.
At best, this affirmative defense can have an effect on the sentence, but in the worst case, one does plead guilty. You might face less or no punishment if someone threatens you or otherwise puts you under duress, or you might cut a deal with the prosecution. But you are still entering the record with a (partial) guilty plea because you affirm that you did it.
However, the big problem is, that you plead guilty and now you have to show that you were under duress and had no other chance but to act the way you did. Merely being influenced does not give rise to the needed amount of duress, just like being aroused doesn't. Even being ordered doesn't give enough rise to have duress: soldiers are explicitly forbidden from giving or obeying illegal orders!
Also, the requirement is not what you thought was right, but what a reasonable person would have done and thought. As Collin pointed out, being totally misinformed about a situation might not establish duress. Most certainly, listening to someone who has a reputation of making between 12 and 23 wrong statements per day for 14 months straight and who ended his term on a tally of 30500 wrong claims would any reasonable person cast doubt on the statements. The speech wasn't even orchestrated specifically to rouse people into riots. And even if it would have been designed to rile people up to demand the total war and start it then and there, duress would still be absent!
In the end, rioting in the absence of someone forcing them with something as drastic as strapping a bomb to their neck is someone's own choice thus the "I was incited" defense is not available, and "I was told to do something illegal by a figure of authority" is explicitly not a legal legal defense.