To be honest I'm starting to think that IV problem isn't because it was too serious, but how it fail to be a serious game
I mean, how am I supposed to take it seriously about Niko came to LC to start a new life when you ran over a thousand civilian and fire RPG everywhere
This is my opinion though...
It's simple: assume everything that happens in free roam isn't canon to the storyline.
How could you justify CJ or Tommy working as a vigilante for the police knowing that they're well known criminals in the city/state where they live?
How could you justify Claude being able to work for the Yakuza when you can just pick up a M4 and rain hell down on their thugs everywhere in the map, and then go play amother mission where Asuka is not even aware of what you did?
How could you justify Victor Vance complaining about not having money to afford the treatment for his sick brother? When a Ashtma treatment in the 80's shouldn't cost more than $20,000?
(Victor has that amount of money after doing about 10 missions of the story)
How could you justify Michael and Trevor, of all people, working as taxi drivers(there's even specific voice lines for then when they accept a fare) when Michael already says in the story that robbing banks is all he knows how to do?
Hell, how could you justify Claude, Tommy, CJ, Toni and Victor taking up a side job as paramedics when they can kill people on a daily basis???
It doesn't make any sense to think these things through and expect some kind of consistency of the characters in a game where you have a gun, a car, and a whole city to do as you please.
That's why you must understand that all game's narrative follows a determined path and whatever happens in free roam is all up to the player. And IS OPTIONAL, I might add.