It's not simply a case of leaving her though and that needs to be stressed.
When you go on an expedition like this as an experienced professional guide you should bring the appropriate equipment and you should risk assessment ability. You should be aware of the conditions and chances of changes in those conditions. You should keep aware of whether someone is struggling in the group. Then if you need to go for help you leave them in a appropriate condition.
Incidents like this shouldn't happen in this way because protocol dictates there are many things that could have been done for safety reasons but weren't. The ideas is each item of safety protocol creates a layer of protection and that a disaster shouldn't happen unless you have the rare occurrence of all the holes in the Swiss cheese slices of protection aligning exactly which is a freak occurrence.
In this case, there are multiple layers of protection missing. The press has honed in on the fact he left her. This is just one of the failings.
Tbh for the most part the law in the UK already more or less operates like this for outdoor adventure. We are generally stricter for outdoor adventure than anywhere else in the world. Certainly our training protocols for guides in climbing and kayaking are the best in the world and this means British trained guides are sought after and regarded as some of the best. Even with Brexit creating a barrier it still means there's a certain demand for our instructors. British qualifications tend to be recognised elsewhere in Europe for this reason too.
I do think there are other countries in Europe that don't have standards as high as here. Frankly there's outdoor adventure activities that are run that should not be. It alarms friends of mine who are qualified outdoor adventure instructors when they see it. They know there's disasters waiting to happen - and will in time happen. They had been predicting the paddleboarding incident in the UK for some time because they identified numerous problems with the culture and governance of the sport and were not remotely surprised by the incident and the findings of the inquiry. They knew the day it happened what had happened without having access to information - it was completely predictable.
Tbh it sounds more like it's a long overdue ruling.
Sadly it will continue to occur in other places around the world with people who simply do not have the ability to safely do an activity being taken out by instructors with a lax attitude to safety. Brits on holiday often don't understand the difference in the level of guides because we almost take our strict rules for granted or don't understand the legal protections we have in the UK. It means doing an activity abroad can be a risk business.
I am not surprised by the ruling. Hopefully it's a wake up call for other European countries to change their laws and improve safety protocols. It will save lives.