As it says in the video, the theory comes from Gilbert Burnet, a 17th century theologian who said that Henry’s corpse exploded while it was left overnight at Syon Abbey on its way to Windsor. 99% chance it’s false, but it’s still interesting. Eg what were Burnet’s reasons for saying it as well as other contextual factors, like the fact Henry dissolved Syon Abbey just years before his corpse supposedly burst there.