To say you're worried about 18 year olds operating rides is daft, they do get trained for a lot of hours on the rides, pass medicals and have to do a written test (or at least they did, it may have changed since)... There's also a lot of 18 year olds who are more mature than 24/30/45 year olds as well... Towers also don't tend to have that many 18 year olds operating the big rides (same for Chessie and Thorpe I'd say, don't see many 18 year olds operating Stealth), so it's a rather unfounded fear...
Of course, you usually cannot train for an incident like this, indeed, the odds on this event happening are the reason everyone is so surprised that it has happened...
I'd still be more worried about riding an Intamin with a lap bar because they've chucked plenty of people out of them than riding a Gerst...