Visible crew/equipment: At the diamond exchange, when Mr. Freeze and his goons are by the wall safe, the shadow of the boom mic is visible in the top right corner of the screen. (00:13:50)
Other mistake: When Mr. Freeze is moving through the room evaluating the diamonds, the tanks on his back can be fire extinguishers. There is no way that the "weapon" attached by hose to them will work, as the handles have to be squeezed to discharge.
Answer: There were three well-known actors who played Mr. Freeze, each one a different height, weight, and physique. As these were notable guest stars, the costume designers would adapt the costume to best fit each actor who likely would want to avoid comparisons to the other Mr. Freezes, incorporate their preferences, as well as refresh the look, rework whatever didn't work in previous versions, and so on.
raywest ★