Factual error: When Ray leaves his wife Gina and his car is hit by the truck he should still be in England, but when he is being chased through the streets he is in South Africa, the cops in the car are not in English police uniforms or vehicle, police livery is incorrect, and all vehicles have South Africa plates, not English number plates.
Continuity mistake: The protagonist, Neil and Kat are in the back of the yellow ambulance in the parking garage. Neil checks on Kat, after that he removes plastic gloves from his hands and throws them into the trash right next to him, 2 cuts later he again crumples a pair of plastic gloves. (01:46:15)
Deliberate mistake: The suit, rather than using many large cameras, should be created with many imperceptibly small cameras in between monitors. We need monitors to see what is on the other side of the suit, not camera lenses.
Character mistake: The Rufus hologram states that he first brought the phone booth to the Chosen Ones (Bill and Ted) in 1989, referencing events of the original film. While that was the year the first movie came out, it took place in 1988 (indicated by the opening title card and dialogue throughout the movie).
Other mistake: Isaac was able to break through his wrist restraints (taped to arms of a chair), escape two androids, quickly find and escape with Sara (while other androids started pursuing) - during a "full security lockdown" in a facility previously unknown to him. Isaac would not know the building's layout or where doors - and an exit - would be, but he had little problem getting out during lockdown while numerous people and androids were chasing him.
Revealing mistake: The "baby" looked quite "rubbery" at times and its limited movements (even motionless) and lack of sound are indicative of a "fake" baby (doll) most of the time. The baby was mostly kept covered in some kind of box and did not even cry when the mother was running with it (while in her arms or in the box). (00:14:35 - 00:20:30)
Continuity mistake: Within a scene, Xanthe's disheveled hair often has a different number of curls/waves (especially on the sides) and the tightness/ looseness varies. Sometimes some strands of curls look like loops sticking out sideways; sometimes her hair looks almost straight on one side. The nature of the curls may vary with front and back views at times. In one scene, she had about three loose waves on the left side of her hair then suddenly it looked almost braided (many waves). (00:07:21 - 00:07:51)