Strange.

https://www.itv.com/news/2020-02-05/family-of-father-and-children-who-drowned-in-costa-del-sol-pool-win-right-to-continue-investigation/

Given that the US have already cleared Spain of any wrongdoing.

https://www.bbc.co.uk/news/world-europe-51384434

But then that does mean all liability rests with the Brit.