At dire risk (?) of thread drift, WLD's shtick above might well make a question for a Torts tutorial on Causation and Remoteness of Damage.

Should there be a written contract between the Organisers of the Burghley thrash, and the volunteer performers, I will lay that there will be a Clause to the effect that the volunteer performer indemnifies the Organisers/Burghley House.

PLI Insurance is recommended for Allotment gardening . . .