Here are some photos and video of the dead reindeer.
The rocks must have carried the current to all those reindeer.
http://www.cnn.com/2016/08/29/europe/reindeer-killed-lightning-trnd/
Used to spend time on rock and ice in the mountains.
Lightning is a common threat.
We would try to find a sheltered place squat down to minimum height and only boots touching the rock.
My boots are made with wooden screws, metal transmits the cold and electricity!
Now, unsure as to how effective that approach might be?