I suppose this verdict took some time to reach a conclusion, and cost a small fortune to reach that conclusion.
HondaMan seems to have the ideal suggestion about possible breakage.
Bit like some of our local school's telling parent's that they cannot drive vehicles onto school property, because of the possibility that a child will get knocked down. Yet at the same time, the teacher's and deliver driver's are exempt from this ruling!.
It claims to have happened at an unnamed campus owned and operated by a private company.*
As is always the case with these HSE myths, the origin of the story is unknown.
Reminds me of the persistent rumour that Bob Holness from Blockbusters played the sax solo on Baker Street. This was made up by Stuart Maconie for a spoof news page at the back of the NME, but somehow years later it was repeated on the web and is suddenly 100% true.
btw Bob Holness was the first James Bond - he played Bond in a 1956 South African radio production of Moonraker