Revealing mistake: Before Howard rises from the float as Turbo Man, we see several shots of the band marching down the street. In two shots you can briefly see Howard (as Turbo Man) in the background on the float. This is before he is shown coming out. (01:03:40)
Continuity mistake: When turbo man takes of his helmet at the end, his head gear has completely changed, he is no longer wearing the pink neck collar or head covering, or the bits that cover his ears that match his costume, he is wearing a normal helmet.
Continuity mistake: When the cop salutes Turboman at the parade, the coffee he spilled on his gloves minutes earlier has mysteriously disappeared, as have the marks all over him from the explosion earlier.
Revealing mistake: The parade is supposed to take place around Christmas, but in some scenes looking down from above, we see very short shadows under the floats and people (indicating filmed during summer). At Christmas, shadows are long all day especially in Minneapolis.
Other mistake: When Howard, as TurboMan, is stuck spinning around in the sign at the end, the parade crowd disappears.
Continuity mistake: Howard arrives back at his home in a tow truck. It is obviously late in the day judging by the sun angle. In the next scenes however it is afternoon. The parade takes place in bright midday sunshine.
Visible crew/equipment: When Howard first pulls into the empty lane, a camera shadow is visible on the car.
Continuity mistake: In the scene where Arnold trips up Sinbad with a remote control car, as he slips upwards the car comes to a halt. We see a brief shot of Sinbad on his back after he's landed - the car has vanished. His post bag is also closed, and there's nothing on top of him. But in the next shot where Arnold runs past and says 'Aww Poor baby', he is covered in letters. (00:20:35)
Continuity mistake: When Howard is drinking beer with the reindeer he looks at Jamie's drawing. Then when he says "It's time I started keeping my promises" the drawing which we can see behind him has changed into a completely different drawing. (00:56:50)
Other mistake: When Howard is running behind the car driven by the lady in the fur coat, he's always shown directly behind the center of the car, but when the lady looks in her side mirror (from her point of view), Howard is in the center of the mirror. In reality, she would only see a part of Howard's left side in the reflection (not his whole body).
Continuity mistake: When Howard is trying to stomp out the fire, in some shots, the fire appears to be in a different spot than the previous shot.
Revealing mistake: When Howard arrives at the Mall of America he comes down an escalator. We then see a shot of the gathering crowd in front of him. In this shot you can see Howard with a woman in light blue with her hand on his left shoulder as he pushes his way through the crowd. This is before he joins the crowd. (00:26:10)
Visible crew/equipment: Right before Turboman runs into Booster, the camera is showing his point of view. Its shadow, with wires etc. can be seen on one of the men moving the lift.
Answer: Most likely, she decided to keep it and not want to give it to Howard which is why she put it in her mouth.