The mercs in the brown Ford sedan are tailgating Val's yellow station wagon, yet in the interspersed closeup shots of her driving her car, there is just empty road behind her, with no following car visible out of her rear windshield.
Val proudly tells Jaime that the homing device she installed in Max's body can pinpoint his location up to fifty kilometers away, yet Val later reminds her nephew Bobby that the dog's transmitter range is only five kilometers, and strongly cautions Bobby not to take Max too far from home when they go for a stroll around town.
The bad guys approach Bobby/Max in their van as Bobby/Max pass a transition between a stone and brick wall (the chief bad guy remarks "Make it fast, I'll take care of the kid.") The van then stops short of the transition in the wall and Max is kidnapped before reaching the point he was shown passing moments before.
Aunt Val tells Bobby that their deceased relatives went missing for several days because their plane did not have a reliable homing device. So when the crash site was eventually discovered, there would not have been any flaming wreckage as is shown in Val's mental flashback, since anything burnable would have been consumed long beforehand.
The metal post tips over and pulls out of the ground "all on its own", without the rope's pulling on it; the rope is slack during the final heavings out of the ground of the post and its concrete anchor. Obviously the post is being manipulated by an unseen crew-member and/or lifting-device.
The bad guys take photos of Bobby playing with Max and drive off taking a left at a stop sign. The scene ends as Valerie's yellow car is entering the intersection and taking a right towards the camera. We then cut to a scene in the hospital. The intersection footage then resumes where it left off with Valerie's car approaching the camera and pulling into a driveway (the bad guys' van still visible.)
The proximity tracker's digital display sometimes does not change (advance up/down to indicate an increase/decrease in distance that Max is from the tracker) in hundredths of kilometers, even though Max is shown to be running at full speed.
The rope that Bobby tied to the metal post in an attempt to "cheat" at the tug-of-war game does not stretch taut at the appropriate places; it is very noticeably slack "behind" Bobby (the portion of the rope between his gripped hands and the post) when Max is supposedly pulling on it.