I can't provide proof, but I _know_ that I tweeted @adom_dev around the time of it's kickstarter and one of the Baldurs Gate EE devs about gemrb around the time they announced that project.
I can't prove that it was deleted. My first tweet appears to be from 2012 but I joined in April 2007 and definitely tweeted once then. (I was wrong about it being 2006)
I'm pretty sure that I changed my handle at some point. I'll try to remember what it was and search the internet archive.
How does one prove a negative? A deleted tweet from 2006 where nobody has taken a screen shot. It's not an active account like POTUS with the entire world watching specifically for catching deletes. I'm seriously asking