In the Q sequence, more or less in the middle of the film, Q is sitting on a wheel chair, with a cast on his leg, then a kind of rocket thing is shot out of the cast. Seconds after, the cast has disappeared!!! I reckon there is no time for him to put it away, but the first time I saw tne movie, i thought it was the cast that went away from his leg, but if you watch it attentively you can see the rocket launcher stays firmly on Q's leg and the rocket is shot out of it!