I AM NOT AN ATTORNEY, THIS IN NOT LEGAL ADVISE!!!
The dog "hit" was most likely the PC for the search. You have the right to ask this question and they need to answer. Also, no Miranda required as you were NOT under arrest. Had you asked to leave without answering ANY questions, they would have had to make a decision right then; arrest, release, detain as witness. Otherwise they have to cut you loose.
Non-compliance is NOT PC for a search (the Supreme Court has already ruled on this one)! There needs to be more. They need to have "reasonable belief" that a crime was, has been, or is about to be committed. Then they have to continue the investigation in order to gain PC. However, here the dog hit WAS the PC.
Next time, they can search the plane as part of the dog hit (without the dog, they have nothing). If they ask to search, the answer can be NO. As far as the questions, tell them to pound sand!!
Just my thoughts.....................