Let me assure you, the thread was NOT deleted on purpose. Rob E did explain just what caused it to go missing but my memory fails me any details. It was just a unfortunate mishap, not intentional at all.
Jumbo - I think you are referring to Rob's post in the Questions Forum a few weeks back:
"We experienced a hard drive failure. We took the most recent backup and recovered, however there were some database corruptions. A small number of threads were lost. I made an attempt to recover these, but couldn't do it without further corrupting the database. No preference was given as no threads that were lost were restored."
Here is my professional opinion (without actually talking to Rob E) as to what happened. I have worked as a database programmer, and one thing that you need to understand, is that any file (for example, the big/small comparison thread), is stored in multiple locations on a hard drive on a server; (You may be surprised to know that the big files on your PC aren't stored in one spot.. parts of them are stored in different locations on your hard drive, and reassembled when you open them)....and the bigger the thread, the more room it takes up, and the more places it is stored. (and it was big thread, with lots of pictures, thanks to Dinklet).. as a result, when the database was corrupted, I suspect there was a higher probability that a part of the thread was corrupt.
So, I agree with Jumbo, don't think that Rob E hated the thread, or had a personal vendetta! Stuff happens!