Fluke? No. Uncommon, somewhat. I have had games just like that, and just like the other posters, they wreck face some games too. I thought getting grounded against a las weapon was bad, but I cringe at getting markelit? Down..
Area terrain is good, but by no means a sure defence. Sometimes the dice gods just aren't with us. My last game against daemons saw his warlord get vaporized by Slaanesh. Rules may be flimsy sometimes, but all part of the fun.