Callie refers to a hollow point bullet as a "cop killer". Hollow point bullets are a common form of ammunition. Armor piercing bullets are what she was referring to.
Jim asks about the military guy's "service revolver". The military does not issue revolvers, and has used semi automatic pistols for decades.
Walkie talkies can be triangulated. Manus says that they can not. 2 or 3 Radio Direction Finding sets could easily narrow down the search area to less than 1 square mile. RDF gear is used to find Radio signals all the time.
Colleen says the portable radio has a range of 15 miles. Even with South Florida's flat terrain, these radios would only work perhaps a mile away from each other. Additionally, the receiver radio was shown as having a dead battery, while the transmitter (which uses much more power) was still going.
An E.R. nurse cannot order a psychological evaluation in Florida. This is reserved for courts, cops, and certain medical and other professionals (a psychiatric nurse does qualify, but not a "forensic" nurse).