I don't think he did the wrong thing. Maybe not the wise thing, but you can't argue with results.
I am offended that people would accuse the cops of planting something. If you do not trust the police, start a petition and get rid of them, but do not impugn the character of the police because you have read too many e-mail forwards.
After Hurricane Ike, there was a tree branch leaning on a power line about to be set afire. The line arced power into the tree, the tree smoked. We called the fire department. LEO's responded first and got pissed off because in there opinion there wasn't a fire. One of them asked to use my bathroom. I let him. He might have been doing a plan view search... He might have just had to take a leak.
Would I have consented to the search. Doubtful, but then again maybe so. Better a search than a no knock warrant in the middle of the night and getting your dog and possibly yourself ventilated.
The LEO's might have heard some tips and rather than get a warrant and kick in doors and all that, decided to go and check out the resident. Crackheads often roll out stupid intel. Just ask the officers in Atlanta if they wish they had gone and talked to the old lady. You can't complain on one hand and then complain on the other... It is just annoying.