Most certainly. Someone can get arrested for having a drug paraphanelia as long as it has been used for pot. They would obviously confiscate it and send the residue to the lab for testing and of course if it came up positive that person would be "boned". So even a single bud or stem is enough to get arrested though it really depends on where you are and who is catching you. If these guys arrest you then they're complete pricks with nothing else to do. This one time I got busted on campus for about a half ounce and a little less than a quarter with 12 counts of paraphanellia as well as about a case of beer and I still didn't get arrested. They just issued me a citation and told the school which is what really got me in trouble....but my advice to your friend is that in spite of all the shit that he's gonna have to deal with, this too shall pass and one day as long as he keeps his head clean he'll be alright and back to his life again.