I've anecdotally heard that it's possible to go from a TN -> Green Card. Light googling is pretty mixed on the subject; one side takes the stance that it's strictly not possible and the other says it is, but a risk.
Can you comment on your take? Is it possible to do this, what are the risks, and would you recommend it vs. trying for the H1B lottery?
It's also interesting that your friend managed to stay in the country despite his i-94 running out. I didn't think that could be done.
This gives me a lot to think about, thanks!