good luck on this one because first off, landlords do not have to give advance notice before entering property. if it were an emergency situation in which a leak in your apartment was causing damage in another unit, no advance notice would be needed. in an emergency, no advance warning is needed when you do not own the home in which you live.
second, just because the police didn't show the warrant doesn't mean they didn't have one.
third, cops can, will, and do get warrants on hearsay all the time. it's called a confidential informant, which will be listed right on the warrant. in any case, a landlord with pictures of a tenant's grow up is sufficient evidence to get a warrant.
finally, from your description, it sounds as though the landlord knew exactly where your grow op was. now why might that be? sounds like she had some suspicion or prior knowledge of the operation before she entered the apartment.
sounds to me like you need to pay the $100 fine and take this as a warning. i would move as soon as possible because you're obviously not safe growing there any more. furthermore, next time around i would be a little bit more careful about divulging information about my op if i were you. loose lips sink ships as they say.
drug laws in this country are archaic and are set up fundamentally against violators. it doesn't matter if this protocol or that protocol was or was not violated. regardless of what people think, the justice system can do whatever it wants to whoever it wants, at any time. nobody is safe in america.