Factual error: In episode 17, Danny's Camaro is subjected to a number of bursts from a mini-gun, riddling it from stem to stern. In episode 18, Danny's daughter mentions that he had just had it repaired. There is no way an insurance company would not total that vehicle, since it would require replacing or using "Bondo" on virtually every body panel, not to mention mechanical repairs.
Factual error: Kono is driving a 4-cylinder Chevy Cruze in pursuit of a V-8 Mustang, and manages to stay right behind it.
Factual error: The plane taking McGarrett from Panama to Mexico purports to be owned by a Mexican fishing company. But the registration number on the plane starts with an N and has 5 numbers and a letter. First of all, a Mexican aircraft would not have a registration number starting with an N. That is reserved for aircraft of US registry. All that aside, the registration number is invalid. US aircraft have at most five characters after the N. The registration - as I suspected - was shown to be in an invalid format when queried in the Federal Aviation Administration database. (00:11:18)
I Ka Wa Ma Mua, I Ka Wa Ma Hope - S8-E10
Factual error: If you put explosives on drywall it will obliterate it, not put a small hole in it.
Factual error: In Steve's office behind his desk is a model of CVN 65 USS Enterprise. The island superstructure is back to front with the Bridge actually facing the rear. This glaring error is present in all episodes to date.
Chosen answer: They are Junior's SEAL buddies.