The old Urban Myth about window testing on High Speed Vehicles?

I first heard it in relation to the British High Speed Train, but it's had some mileage.

Apparently, British Rail engineers were testing the resistance of the front window on their new high speed train, designed to travel at 250 mph. The front window was engineered top resist the impact of a chicken at full speed (actually 300 mph to be sure) and tests were being carried out to check this using a chicken fired from a gas-gun.

Unfortunately, the window totally disintegrated on every test, and the chicken embedded itself in the back wall of the driver's compartment, after passing through the window, the crash-test-dummy, the seat, and eveything.

British Rail technical staff contacted NASA officials to check whether they were following the right test procedures, since the results were so far outside expectations (The window was engineered to stop a pheasant, or a housebrick, but was failing with a standard domestic chicken)

NASA sent an engineer to oversee the next test, and he watched, then burst out laughing as the window shattered yet again.

When asked by his embarassed and annoyed hosts why he was laughing, and what they were doing wrong he said:

"First, THAW the chicken"

It appears that this joke is not familiar to NASA engineers. Frozen stuff is inherently harder and more damaging than warm stuff...