I have 2 storyline complete saves.
One for if i ever feel like adding on some % towards 100% completion, No cheats obviously.
The Second for shoot outs, free falls , stunts , Ped squashing , Cop killin motherfuckin fun
About 2000 something times cheated in that save lol.
That same fucking thing happened to me man!
I was so pissed off thats why i never cheat through the storyline ever, Its happened to me on Vice city before as well. Cant remember correctly but it was a mission to race the fat guy in the sabre turbo or Drive that dude to the hospitol that blew his arm off.