And as expected, the turtle allows this to happen. What a leader!
Just as a matter of curiosity, what would you have the Majority Leader do about this.
Seriously, not his fault. It is trivially easy for a single senator to disrupt regular order. What holds them back is peer pressure. When one party binds together, the peer pressure angle is gone.
The Senate being simultaneously "in session" and "nearly vacant" is done by unanimous consent.