Continuity mistake: When the girl is asking for Dom's number at the end of the first race her hair is in her jacket in some shots and not in others. (00:43:00)
Continuity mistake: Dom lets go of David Park and Brian rushes forward to grab him. Dom vanishes instantly, for Brian to get past him. (00:29:50)
Visible crew/equipment: After Brian transfers Mia in the FBI building, there is a shot of a red car with chrome bumpers. In the bumper you can see a cameraman walking forwards with the camera. (00:24:15)
Revealing mistake: When Dom and Letty get out the car at the crash scene, there is a light reflected in the paintwork quite low. When the camera pans out you can see it's not the moon due to its position, and there is no other light source around that could cause the light to be reflected so low on the car. (00:19:15)
Continuity mistake: When Mia hugs Dom in the garage, her hands keep changing position and grasp on Dom's shoulder. (00:16:50)
Continuity mistake: When the truck driver shoots at Dom at the start, we see his window smash in on him. Camera changes and it smashes again, but this time it smashes out, on to the road. (00:03:50)
Visible crew/equipment: Just after Dom says "T, you're up," a camera moves across Han's truck and up to the window. When it moves the shadow of the camera can be seen on the orange paint, moving. (00:03:00)
Visible crew/equipment: When Han does the handbrake turn right at the start, you can see the camera car reflected in the chrome bumper in the closeup. Slo-mo helps but is not required. There are also skid marks from previous takes. (00:02:00)
Continuity mistake: When Dom crushes Phoenix between the Camaro and Impreza, the hood of the Camaro is badly damaged and denting up. In every shot afterwards, the Camaro is just fine. (01:35:50)
Answer: No it doesn't ignore 2 Fast 2 Furious, Brian even references it a couple of times. In that movie, Brian was promised a 'clean slate' if he helped them out which presumably gives him the option to rejoin a law enforcement agency. That he chose not to open a garage with Roman is pretty much redundant, Brian simply got a better offer, and as he stated in Fast & Furious with his conversation with Mia, "I'm a good liar".
GalahadFairlight