I saw that aswell last night and couldn't for the life of me figure out where they were shooting from until I looked up. It switched sides later where we pod dropped on their aircraft pads.
EVIL tactic used on us last night. Guys deploying to the top of those thin towers with the 4 X aircraft pads. Near impossible to take them out (deploying on the top leaves you disorientated, jetpacking up there can leave you outnumbered and the angle is too tight to get any decent shots away from down below), they can reign fire down on everyone below, meaning that it is very difficult to take out air support or give cover to the people below.