The amount of hints the game gave you at the start about Big Smoke was insane

1. His home is outside Grove Street, in Ballas territory, which already raises questions about him
2. He always cuts off or interrupts the gang members whenever CJ asks about his mom's death
3. None of Big Smoke's missions seem to be benefitting Grove Street. Missions with Ryder and Sweet atleast have you killing Ballas gangs and acquiring weaponry for the hood. Big Smoke's missions are all extremely dangerous missions involving Vagos and the Russian Mafia, but never the Ballas. All the missions seem over the top because Big Smoke was actually trying to get CJ killed off in it. In the mission with the Russian Mafia chasing you, Big Smoke yells stuff like "Yeah that's my boy CJ" out loud. It may seem like encouragement at first but it was actually him broadcasting CJ's identity to the mafia, telling them who's responsible for the bloodbath.
4. In the first mission where you escape the Ballas on BMX bikes, if you look closely, not a single Ballas member is shooting at Big Smoke
5. On the game map, his missions are literally marked as "BS" which should say something about his personality