Seals aren't on the the humpback's menu. They feed on krill up to smaller fish like mackerel. Maybe it mistook the kayaker for an orca or shark and was just trying to defend itself?
That is interesting, but I have seen Videos of Orcas tossing seals all around like they were toys.
I have a Dog that killed all my chickens,
she wasn’t malevolent but was playing!
She is a 140 pound Great Dane.
Never tried to eat one of them just gave me her disappointed look as to why they quit moving.
We are fixing the chicken coop so no more free range chickens.
Perhaps the Orca is just playing?