I don't have enough current experience to help you specifically but LOS used to be a veritable nest of thieves and rip-off artists, all in official uniform, who existed simply to part travellers from their money.
I wouldn't spend one minute more at the airport than I had to.
Haven't you got a friend/contact/colleague who will share a beer or 2 with you whilst you kill time?
There are many, many airports I wouldn't want to spend 5+ hours at and LOS is fairly near the top of that list.