When the female shooting victim is being examined poolside, then at the coroner's office, her bullet wound is in the exact center of her chest, but when her shooting is replayed, the resulting wound is to the left of center.
U.S. territorial waters extend out 12 miles from shore, not 3 miles as stated in the episode.
At 8:00 and 8:35 we see a semi-automatic handgun being fired in slow motion. Instead of an empty casing an unfired cartridge is ejected.
When they show the 1st flashback of Rodrigo firing, you can see the round ejected from the breach is an intact full round but in the flashback he is firing a round (you can seem an ejection from the muzzle). A gun would only eject the bullet casing not a intact round. And to conduct the GSR test would mean the round left the casing allowing the gunpowder to ignite and eject out, intact bullets don't allow for gunpowder ejection.