In addition toRed Dead Redemption 2’s required story missions, the game also includes optional fishing adventures such as “The Veteran” storyline. Not only is this mission more difficult and action-oriented than previous fishing missions, but it also only becomes available in Chapter 6, when ...
Then there's the scene later before the first heist, where Lester mentions he was working with someone before Michael turned up, but disregards them because they're "too unpredictable" or something. He may or may not have been talking about the GTAO protagonist. There's also another point ...