Hi folks. I (like someone else earlier) did a quick sign up to this board. Perhaps I can answer some of your questions. Like you, I hate being in the dark about a tragedy so close to my passion. Divers have always been a tight-knit community, or at least east coast wreck divers are. I assume it is the same here.
I am (was?) one of Tim's friends and co-workers. His cubicle is (was) less than a "block" from mine. My own diving experience is mostly tech/DIR. At present, I am "inactive". You can find my photo in the book "Diving the China Wreck" by Mike Bullard.
Tim had been planning a vacation to Belize for quite some time now. A few weeks ago, he got his PADI Open Water for this purpose. The Blue Hole was his goal for the trip. I imagine that he heard about it during dive training. Along the way, he kept me posted on the play-by-play. His excitement building with each passing week. A couple weekends later (my timeline may not be exactly correct), the shop took him for his "advanced" training. A couple weekends after that for another certification card (I do not recall which). A pile of confidence building cards with no "real" dives under his belt. Where was that "instructor"? Where was his "dive buddy"? These questions I do not have an answer for.
If you detect a hint of disdain in my words for the way PADI does things - you would be correct. But alas, before the PADI instructors flame me - I will admit that us techies lose people too - even those with hundreds/thousands of dives. It is a tragedy every time. The more information we have, the more we can learn about avoiding the dangers.
The thought crossed my mind that I could have possibly been there, or I could have impressed more caution of the dangers. In the past, I have been on two boat trips that resulted in someone needing a re-compression chamber (not myself or my dive buddies - thankfully). I should know better. Instead, I "egged him on" to enjoy diving and learn more, speaking often of crazy east coast cold and murky dive tales in 6 foot seas...