He has weapon surge mods on his boots which lets you pickup orbs of light to get armor charges. I believe there is a bug in the game right now when you have too many mods equip. When I run into this bug and i take off my chest armor mods it lets me pickup the orbs. Also if you have just the right amount of mods on your gear it lets you pickup the orbs and get armor mods and not have it decay even with decay mods. Hopefully there is some clarification on this issue soon from bungie