Do I have a chance at getting my case thrown out?

The police knocked on my door while we were sleeping. They initially said they got a noise complaint about a loud party going on at our address. Then they said they could smell marijuana outside our house, before we even opened the door. We had been sleeping for nearly an hour and hadn't opened our door for nearly 2 hours. They ultimately said they never had a noise complaint. They said someone anonymously called, gave our address and said there were "drugs" in our house. The cops said we could let them in the house and show them where the "drugs" are and they would issue a citation. Or if we refused, they would freeze the environment, get a warrant and search our house. We went with the citation because we had no choice. We realize being able to smell marijuana gives the police probable cause. But we know they couldn't smell anything from our driveway or porch, like they said. They lied to get us to open the door and then said they could smell it. How is that legal?