Lazy, lazy plot development
Maxwell; "You can't have salmon from British rivers as the fishermen are kicking off. You can have these farmed salmon, or no salmon."
Jones: "As an expert, I know these farmed salmon will never run. So I guess it'll have to be no salmon."
Maxwell: "Ok, cool."
A short time later...
Jones (with huge excitement): "Sheikh! Sheikh! Great news! We can use the farmed salmon! They CAN run! They WILL run!"
Sheikh: "Well that really is great news, you obviously have done some research or have uncovered new evidence to suggest that farmed salmon are bad ass and can indeed run upstream."
Jones: "...Well, actually no..."
Sheikh: "Oh, ok... So, how do you know they will run?"
Jones: "...I just know!"
Sheikh: "Really? Don't you want to explain this sudden U-turn that will hugely affect the outcome of the project the film is about? Won't the audience who haven't dosed off by this point find 'I just know' a bit hard to accept as a believable reason for you changing your mind??!"
Jones: "..."
Sheikh: "..."
Jones: "Nah, we'll be ok."
Sheikh: "Cool, lets go to Yemen."