I go back to the start of this Incursion where Namor and T'Challa are watching this GS Earth. Namor takes out a wine bottle and drinks from it and hands it to Black Panther and they laugh together about how this will all end up alright. On some level they both joined in with the same tragedy that was going to play out 2 hours later, like they both had premonition that something awful was about to happen and all you could do is laugh about it.