How did the law firm "drop the ball"? If the kept him in the country for more than a decade despite his having a conviction for distributing drugs, it seems that they were doing something right. If you've read other threads, or picked up on the general atmosphere of the deportation proceedings, you have a sense of how seriously the USCIS treats drug trafficking convictions.

Something else: Criminal charges almost always end with a plea bargain. When somebody is charged with intent to distribute based only on quantity, and there's some ambiguity in the quantity, it's not unusual for the plea bargain to be to simple possession. You make it sound like no plea bargain was offered. Was the conviction in fact the result of a plea bargain? The sentence suggests to me that there were serious aggravating factors here, such as his being accused of selling drugs to minors at the party, and perhaps plea bargaining away the "distributing to minors" part of the charge while pleading guilty to intent to distribute. Also, why would he take his entire, oversize personal stash to a party?