what specifically has he said
Theres a tweet video in the PDT, but essentially he was saying the risk of myocarditis was higher for those who got vaccinated. His guest told him that was completely untrue. He pushed back and said "no I read it somewhere". Guest told him to look it up. Turns out myocarditis is about 8x more likely when catching COVID than it is from the vaccine. Joe proceeded to then try and argue against that scientific study by saying something to the effect of "well that wasn't what I read, where did they come up with that".
It's just self-serving idiocy.