Ahamard Hall seems like a stand-up dude to me, so I will take him at his word that what he got suspended for was some type of stimulant to keep him awake on a drive from Nashville to Texas, but that doesn't excuse the fact that he took something on the banned substance list. For the life of me I cannot understand why guys continue to take things that end up getting them in trouble.
I don't expect any NFL player to know every supplement that is on the banned list. I would imagine the list is pretty long with a bunch of words that are impossible to read, but that doesn't excuse a player when he takes something that is on the list. Every player in the NFL should ask someone in the know before putting anything into his body that he isn't sure about, and that would include any type of stimulant out there.
It sucks for Ahmard and the team that he is going to miss the first month of the season, but hopefully this will team him to ask first next time.