The song "Jan Pierewiet" is a traditional, pirouetting dance tune (that's the "Pierewiet" bit). The words "Jan Pierewiet, Jan Pierewiet, Jan Pierewiet staan stil; Jan Pierewiet, Jan Pierewiet, Jan Pierewiet staan stil" can be seen as directions, for all they're mostly nonsense words pretending to be a name in Afrikaans: so, "step, pirouette; step, pirouette; step, pirouette — stand still... (repeat)". What would rebooting do to Elysium for a few seconds? Switch almost everything off... so it technically stands still for a few beats, before actively starting to turn again. At the point of singing it, Kruger knew this.
Carlyle only sending one droid out to face off against the attackers initially. Obviously he'd have to put up some kind of resistance, and once the attackers destroyed the first one, they may assume that he was free for the taking. So while they have a false sense of security and come out from cover, his second droid could then ambush them. And it seemed to work well, as Max and the others have a little more trouble fighting off the second droid, and had it of held out long enough, Kruger and his men would have arrived, killed them, and saved Carlyle.