I don't think El Diablo had direct contact with Mario "El Gordo" Cardenas. El Diablo was heavy but he wasn't heavy enough to know the details or whereabouts of the leader of the Gulf Cartel. If he was betrayed it was most probably Costilla that gave him up. There are dozens of other Gulf Cartel commadantes that are higher than El Diablo especially the ones around Matamoros and Reynosa. I see El Diablo as being the front for the Gulf Cartel in the Monterrey metropolitan area. He was appointed head of the plaza of Monterrey metropolitan area so he can get all the heat and not go after the ones in Reynosa and Matamoros where the Metros are based.