I would have left the stern line in place. Removed the bow line (crew member or self) then go into reverse engine which would have moved the bow away from the bank, then untie the stern rope. Much simpler than shown. Good video though.
Or you could just push the bow out in a fraction of the time! Alternatively; helm over and a bit of forward to move the stern out then reverse away from the bank (Seen frigates do that at a Naval base,) if it works for the RN, why not?
