The guy is talking about the 'Sahih el Bukhari' , which is the most 'authentic' hadith collection and the most 'holy' book after the Qur'an - and it's the source of a lot of Sharia laws; which according to this guy, 95% of muslim clerics follow.
Think of it as the Talmud for Muslims.
The guy skimps through the 4 volumes, quoting weird, disgusting, disturbing and some very violent hadiths regarding prophet Mohammad. Like for instance when he chopped hands and poked the eyes with nails of two marauders. Or when he claimed that eating dates in the morning makes you immune to any poison, you should watch the guy when he challenged his superior to eat dates and then take poison, it was funny. Skip to 35:22 for that part.
Or how sexually hungry, like it is claimed in the Bukhari that he was used to f*** 11 wives in one night, and the imam is mocking on that says who are they fooling - and he linked that to ISIS' obsession with sex, see at 22:10.
According to the guy, they're contradictory to the teachings of Quran, like for example he quoted a hadith claimed to be said about Mohammad that at one point Mohammad doubted the teachings of the prophets of Israelites before him such as Abraham (in arabic they called it Bani Israel which literally means 'Children of Israel' is mentioned at least 20 times to refer to Jews and all the prophets Islam believes in), and even it is claimed (in Sahih el Bukhari) that he said that his followers are more important than them (the prophets of Israelis) , and this is contradictory to the Qur'an, at least according to this Imam.
The guy thinks this book needs to be ditched altogether in order to 'reform islam' (I don't agree with him, I think the whole Islam is messed up but ...oh well, that would be a good gradual improvement).
I think this guy is a closet atheist.