He didn't mention terrorism but the same could be said of Saudi too on that subject. No real evidence of the governments involvement in many of the claims made against them. I think it's obvious Iran have their hands just as dirty as Saudi personally.
The war in Yemen very much is a proxy war between Iran and Saudi though, it doesn't make sense explained any other way to me. Some say it's even Russia-Iran vs USA-Saudi.
Saudi's belief was that Iran's government tried to install a proxy government in Yemen(not that their actions are justified either way, neither was the USA's/UKs in Iraq). Ironically, as I understand it, the Iran Revolution came about because many saw the Shah as a proxy/puppet of the USA/west. They helped install him(CIA, assisted by the MI6) and he relied on them to help him keep his power for many years too. I don't see why so many are in denial about the way governments operate, trying to paint one as angels and the other as devils is just not rational thinking to me.