The swimmers never reported the "robbery". They only investigated after Lochte's mom went to the media. The media ate it up because it is dramatic and fits the meme of the mess that is Brazil. The police came asking questions of the swimmers.
Maybe but if the police version is true (unreported self-help by guard who demands payment for damage at gunpoint and then does not report the incident to police), it just shows what a zoo Brazil is. I bet $400 goes a long way towards fixing a gas station in Brazil.
In fairness to the Rio police, if they hear about a crime committed in their jurisdiction even if it wasn’t officially reported its kind of their job to investigate.