Yeah, I would never attach a rod leash to a rod holder. I've broken those Yak track inserts off of the Scotty Mounts. Luckily I caught the mount with a quick dive into the water.

LOL.
I've never been happy with Scotty or Ram rod holders.
Now I'm using the Railblaza mounts with the new AI. When they bring out the new rod holder, game over. But I still would never trust them 100%, always a rod leash attached to the kayak.
Sooner or later you can assume your going to end up tipping over in the drink and anything that doesn't attach with a leash or float will be lost. Just a matter of time, when your most vulnerable. I never assume anymore.
Sorry to hear of your expensive mistake, I'm sure it will never happen again.