At 22:34 there's an empty coke bottle in front of the lawyer. When the camera angle changes the bottle has disappeared from being in front of him. At 22.44 the angle changes again and there's an empty bottle but in a different position on the table.
Agent McClaren is apparently only there because of the travelers, so they appear to have caused his death. Or could not have known about it.
But Agent McClaren would have died in that elevator shaft even without the Travelers being there. As the Travelers stated Agent McClaren was supposed to die in that building during the blackout while pursing Jonas Walker, who originally went on a shooting spree during the blackout and ran into the building in an attempt to evade Agent McClaren. This is why the Travelers chose this meeting place, because McClaren would have died there even without them altering events.
But Agent McClaren would have died in that elevator shaft even without the Travelers being there. As the Travelers stated Agent McClaren was supposed to die in that building during the blackout while pursing Jonas Walker, who originally went on a shooting spree during the blackout and ran into the building in an attempt to evade Agent McClaren. This is why the Travelers chose this meeting place, because McClaren would have died there even without them altering events.
It is never explained why having a drug addict is a good choice for the team.
Close ups of Marcy's eyes show contact lenses. Someone with her disabilities prior to being taken over would find it extremely difficult to wear contact lenses.