If CP-2933 had originally filed for a Bogota fuel+go and then re-filed in flight for Medallin then we would have heard about it by now. He may have used Bogota as as an en-route alternate in order to reduce his contingency fuel on a single flight plan but it is so close to destination as to be of no saving.... In any case that presumes they adhered to some sort of fuel policy... which looks rather unlikely!
From elche's link above
LaMia Airlines the Panama Post alleges that there is dirty money and shady political dealings behind this operation.
It seems strange therefore that they are apparently the airline of choice for several South American soccer teams. In my experience Soccer teams don't usually need to buy cheap... so one might assume the airline is either particularly well connected in the VIP market, or they are #1 choice for some other reason. We understand the crew complement was 9, that's 2 pilots and 7 cabin crew on an aircraft that normally operates with only 2 or 3 cabin crew. Why so many? You might say this is a VIP operation but 4 or 5 would be overdoing it for VIPs.... but 7 for a pax load of 85 ???
What sort of party bus is this exactly ?