He could have landed not on the runway. He departed the runway pronto when he lost control though agressive braking.
He could have panicked. Are you sure he didn't? I'm not.
He could have not flared. He didn't. L. Main & nose wheel, and right leg touched down together.
He could have landed not controlled. He did just that.
He could have not tried to keep the weight on the working wheel. He made no such attempt.
He could have not tried to keep the plane straight by not using the rudder. He lost control completely once on the ground, with no attempt to stay straight.
He could not have turned the engine off at all. What? Not ever?
He could have not used the brakes and so run off the end of the runway. He stomped on the brakes causing the aeroplane to depart the runway immediately. If he'd left them alone he would probably have stayed on the runway.
He could have messed up the approach (since he knew everyone was watching and was under pressure). The approach looked OK. It went pear shaped after that.
He could have ballooned (the plane would have been light). You have to flare to balloon. He didn't.