Ok, after reading 3 pages worth of speculation, I figured I'd actually give the TC some real advice.
This is a common tactic by police officers. They have way bigger fish to fry than your buddy with the QP. They have him on a paper record, DO NOT DOUBT IT. They filed his evidence away, so there is definately paper work on him. He may think that they are watching----They are not. Oh sure, they'll drive by on routine runs throughout your town (if you normally noticed officers drive by occasionally before the raid went down) AND if the officer that is driving by is familiar with your situation than he might give a passing glance---(they do this to keep a tab on what cars are parked in front of your house regularly. They are searching for high traffic that would re-indicate that your buddy is back in business)---
If your buddy shows up to get booked, which the police are hoping that he is dumb enough to do, than he may give a confession and do all the hard work for them. They have up to one year to act on any charge. What the police like to do is wait for as long as possible---make their suspect sweat. Make him nervous, and when he (your buddy) thinks the coast is clear, they hope that he will start selling again, or at least start smoking again. They will be back. It may take 8 months, it may take the full year, but that's what the police want you to think (that you never know when they will be back) Just keep in mind that they will come for him.
This all happened to a buddy of mine back in February. Same story, only they found an ounce and some lights instead of plants and pounds. My friend gave the police every oppurtinity to charge him. When my buddy called his lawyer up and found out that after 4 months that he still hasn't been officially charged nor did he have warrent out for his arrest---did he decide it was time to pack up and move. He moved from my state to Alaska. Your buddy might not have to move that far, but I do recommend that he definately MOVES. Out of state would be the best idea, but at the least out of whatever county that you guys currently reside in. That way this doesn't follow him and he can avoid the arrest. If the police come back and your friend isn't there, they will file everything away and in the end, they only keep his stash. Cheers and good luck to the future.