Smashing the Glass

Today our nemesis Moriarty pulled off his biggest stunt to date. He simultaneously broke into the Bank of England, Pentoville Prison, and the Tower of London. I want to focus on the main heist at the Tower of London. All the reports are telling me that Moriarty attached a diamond to the 2 inch thick glass casing surrounding the Crown Jewels using a bit of chewed bubble gum. It is said that Moriarty then took the room's fire extinguisher and hit the diamond, smashing the glass. But this is implausible due to the nature of the glass. Like in the old spy movies, diamonds can be used to cut glass, but not shatter it. The amount of force needed to apply enough pressure to even pierce a tiny whole in 2 inch thick, heavy duty glass is impossible for a human to supply. We can assume that the glass surrounding the Crown Jewels is every type of "proof" possible, i.e. bullet proof, fire proof, and shatter proof. The laminated style of safety glass has an inter-layer that keeps the layers of glass bonded even when broken so it would be nearly impossible to shatter and separate the glass enough to climb though. I'm thinking that Moriarty must have used some other method to make the glass appear as if it was shattered and the trick with the diamond was all for theatrics.