But as someone who lives in sing I can tell you that fire trucks taking a short cut would not have turned out well.
I would have to agree with that - I remember many years ago at Hobsonville (grass field) in Auckland, a Bell 47 messed up an auto and chopped the tailboom off - the fire appliance at Hobby was one of the Unipower tender rather than the off road appliance normally there.
The appliance launched out of the fire station straight across the grass where it became bogged up to it's axles and there it remained for a day until it was dug out.
Those fire crews know that airport, if none of them drove on the grass it was for a good reason.