Alan Would've Been Able to Overpower Sam

Alan made out that he was a fragile old man, yet it is clear that he is physically stronger than Sam. Sam was younger, sure, but Alan was much more muscular and easily had a good 30lbs on Sam.

If I was Alan, I would've used the first opportunity I had to grapple with and overpower Sam and disable him. Heck, he could've killed him and he would've gotten away with it because of the situation he was in. I would've played dead or feigned sickness in order to lure Sam close to me and then I would've pounced.

How would he then escape? His mother would've eventually have had to become aware of the situation and I would bargain with the mother to release me for Sam's life.