You can't do something such as an air horn because on a golf course there are numerous matches taking place on different holes, it would distract players. Yes someone might get hurt but it is a rare event and isn't really proportionate. If an air horn sounds, likelihood is that thousands of people are going to panic and nobody is really much clearer as to whether it's heading for them in any case. This is a freak occurence and we seem to now be in a litigious society where whenever something happens such as this it must mean that things must change- i.e. putting warning stickers on microwaves because someone once tried to dry their pet off inside one. I do not like this culture of blame that we've inherited from across the pond. I do sympathise with her and hope she gets adequate compensation from insurers, I just think she could perhaps do it with a bit more dignity that's all.
Sorry can't agree here, as you say its a very rare event so its hardly going to cause major disruption, if its the difference in somebody getting seriously hurt and somebody maybe having to take a shot again I know which I prefer. As for panicking all you have to do is make it clear beforehand that if you here this noise take evasive action, ie cover your head and face, anywhere else might hurt but not be that bad
I play golf and as soon as you hear "Fore" you immediately duck and cover your head and face with your arms and hands. Koepka clearly shouted "Fore" so not sure why she didn't cover up.
Its rare that someone gets hurt- its not rare that the ball goes off the fairway... thats the point i was making.