No, sorry dive instructors do not grab a hold of divers and lead them around for the entire dive. If the diver can not function on a more or less independent basis, then the dive is aborted pretty quickly. If you had not been very close to her and hanging on her for the entire dive, she probably would have aborted the dive very early and may not have been subject to the potential injury from an uncontrolled ascent.
Q: What's worse than an inexperienced diver (who doesn't know any better) being lead around on a "tust me" dive?
A: An experienced (DIR, no less) diver (who shouuld know better) dragging around an unqualified diver on a "trust me" dive because he thinks he can handle any type of foreseeable problem.
I'm sorry, I have to disagree too. I dive SE Asia quite a bit and have seen both DM's and instructors holding and leading divers around for the entire dive many times. Sometimes this is due to lack of skill, other times fear, and occasionally equipment failure.
Sometimes it appears to be a learning crutch.