The Doctor puts one finger into the jar and then licks it, but after the view changes back to him from Rose he has two fingers in his mouth.
The Police motorcycle in front of the Olympic runner is an S registration, meaning it was registered in 1998. There is no way the Police would have such an old vehicle on active duty in 2012.
When the Doctor starts sniffing in a man's garden, just before Rose says she can smell metal, the camera is reflected in the house's window.
When Rose is "playing detective" the Doctor asks her if she is "deducting" which means to subtract from whereas he should've said "deducing".