Hi guys, just two cents from a guy who has 195 dives on the logbook and had problems with weights.
1) if the diver doesn't change often environment and type of dives, 200 dives may not enough to experience different kinds of problems and, therefore, they are not sufficient to built experience.
2) if the diver has always dived overweighted, has never tried any other equipment and has always been with the same group of buddies... well, there is a lack of experience and (probably) a lot of bad habits to remove.
3) in my case, the problem with weights started when I switched from wetsuit to drysuit. When I started diving, I was instructed to dive overweighted, and when my fundies instructor wanted me to go with a balanced rig and a trilaminate drysuit, with plenty of undergarment, I just didn't manage it and did a couple of uncontrolled ascent. After, uncontrolled ascents become my demon, and it took quite a bit to remove weights and to finally dive a properly balanced rig (although I never used a crazy amount of weight). With such a low level of experience, psychology can play bad tricks.
Frankly speaking, I think that 200 dives do not make a diver experienced, at all. Maybe, if a diver changes often environment, try to dive with people from different schools, and do a lot of training, 200 dives can make a solid base, but nothing more.
(or maybe I have a serious lack of self-confidence, because I do not feel experienced
)
Just my two cents.
Condolence to the family, this is a horrible tragedy.