Everything seems to point to Shanks and Loki coming to blows over Shanks not wanting Loki to attack the Holy Land too soon. No offense but I think a lot of you are just letting your preconceptions about how strong Shanks can be distort your reasoning. Shanks is already getting wanked as the Child of Destiny who has Haki comparable to Joyboy. It is kinda weird how hard Oda powercliffed PK level fighters but it is what it is.
I get that a lot of other stuff we heard about Loki was a lie, but to be frank, it was pretty obvious since the start of the arc what the narrative purpose of those lies were (Oda wanting to “surprise” the readers by having Loki actually be a good guy, and have a twist with Harald). There really is no clear narrative purpose for everyone to be lying about Shanks beating Loki fairly. There really is no good reason for them to not just credit the entire RHPs if it was a group effort, and I think it’s pretty delusional to think that a character like Shanks would resort to poisoning him or anything like that