Plot hole: Brandt sabotages the mercenaries' explosives so they are killed when trying to escape. No real team of professionals would let the rich yahoo who hired them touch their gear. Nor would they use any explosives he provided without (at the bare minimum) inspecting them first. It's a plot hammer to wrap up what happened to the mercs so they can move on to Brandt's capture.
Suggested correction: So, they knew they would be framed/killed at the end? Also, if he was paying or threatening them, then why wouldn't they listen to him?
Walk up to a professional you have hired and is doing his job. Plumber, AC tech, whatever. Ask him if you can mess around with his stuff while he's working. What do you think he'll say? Especially if your messing with it could cause harm to him.