How did Stritzke take the cash?

In the series The Lost Room, Harold Stritzke has the comb. The comb enables the user to pause time. When time is paused it's made clear that the owner of the comb cannot effect people/objects that are frozen.

Earlier in the miniseries Stritzke is shown in a 7/11 type store. He uses the comb and steals money out of an open cash register. Cash which would have been held down by pieces of plastic/metal in the till.

So how did he do this? Is this a mistake?