NMFS cephalopod expert Mike Vecchione has identified this one as Grimpoteuthis sp. Generally speaking though, "dumbo octopus" applies to one of two genera, Grimpoteuthis or Opisthoteuthis.
The two genera are quite diverse. Grimpoteuthis includes about 18 species (according to marinespecies.org) whereas Opisthoteuthis includes about 20. Although these two genera are separated into distinct families, my understanding is that there is some disagreement over the taxonomy of the group.
The video followed this guy around from the water column down to the rock, after which it eventually swam off..