I am pretty sure they have a "Not Liable for Blah Blah" clause on the ticket when purchased. Not sure about Europe.
Here is a USGA doc covering what we are talking about:
Ticket Holder expressly assumes all risks incidental to and associated with attendance at the
Championship. By virtue of the Ticket Holder’s attendance at the Championship, the Ticket Holder
acknowledges that s/he/ understands all risks incidental to and associated with his/her attendance,
including but not limited to being struck by a golf ball or golf club, and hereby waives, releases and
discharges the USGA,
Chambers Bay
, any and all of their respective affiliated companies and vendors,
participating
players, and all employees, officers, directors, agents, representatives, and/or volunteers
associated with the Championship, and agrees to hold harmless all of the persons and entities listed above,
from any and all claims for damages for death, personal
injury or property loss or damage including all
costs and expenses, which result from the Ticket Holder’s attendance at the Championship. This waiver,
release and assumption of risk is binding on the Ticket Holder’s heirs and assigns