I looked for safety topic and found almost none (just brief mention in introduction). This research’s scope is mental health so it’s understandably out of their scope, but endorsing something should always weight both benefit and risks.
Natural water body never guaranteed to be safe, no matter how it looks on surface. Many lives lost because of OWS every year. Personal floating jacket is bare minimum, won’t guarantee safety either.
If there’s something to mourn, I’d say the lost oppurtunity to have him procetuted (there was a trial about financial fraud at that time).