It happened to me in two cases:
1 - Tavern in Sao Jorge - when the fat man wanted me to kill Mateus Santos. I rejected the mission. When I come back to the tavern again, he started the same conversation again.
2 - Pirate settlement on Nevis - After the animation, I have killed Nigel Blythe. Then Artois Voysey wanted to become my officer. I have rejected him. When I came back to the pirate settlement, I have seen the animation and had to kill Nigel Blythe again. It stopped when I accepted Artois as my officer.
Build 14 beta 4.1
1 - Tavern in Sao Jorge - when the fat man wanted me to kill Mateus Santos. I rejected the mission. When I come back to the tavern again, he started the same conversation again.
2 - Pirate settlement on Nevis - After the animation, I have killed Nigel Blythe. Then Artois Voysey wanted to become my officer. I have rejected him. When I came back to the pirate settlement, I have seen the animation and had to kill Nigel Blythe again. It stopped when I accepted Artois as my officer.
Build 14 beta 4.1