What remained uncertain about Titanic?

Are there important historical questions about Titanic that remain unanswered?

One revealing question is how Alexander Carlisle responded so constructively after his safety proposals were rejected and the disaster proved his concerns justified.

Carlisle's response is treated with some humor because he resisted publicly declaring that his rejected safety ideas had been vindicated. He concentrated on improving regulations and supporting reform instead of celebrating being right. His conduct suggests genuine grief over the deaths and a sense of professional responsibility after the failure. A comparison with Isambard Kingdom Brunel raises the question of how different Titanic might have been if her designer had enjoyed a freer hand over cost and construction.