The bowman on P did point out the Starboard boat (at 5 secs)
I do believe the Case Book is where you go.
I have a lot of opinions on it with regards to rule 15 - Time and opportunity.
Guessing is not in racing rules so Port boat does the following
Sees Starboard boat coming towards him, rule 15 on, Port avoids,
Starboard tack boat raising a spinnaker, turns 15 on again, avoid,
Spinnaker setting way out to leeward, turns 15 on again, no time to avoid .
p.s. Anyone notice the tack was not at the beak. Probably why it set out the back. So maybe the question about "normal position" could come into play. Again we can't guess what a boat and crew will do.