I hope you are able to get other safety protocol in place Peter.
IMO Mill speeds while the retrieve boat is out would be a good idea. It shouldn't be difficult to figure out a "restart" procedure. I have seen a few pictures over the years with model powerboats boats buried in the side of retrieve boats. Getting hit in the chest, scary stuff!! This could have been life altering for you and your family,glad you are ok. I hope they take your concerns seriously.
Are fail safes mandatory for this event? If not that would be a good addition to the safety rules imo.

Be safe!