What you mean is that getting the ball doesn't prevent you from committing a foul, if you tackle in a way that is either careless, reckless or uses excessive force whilst making first contact with the ball. What does not logically follow from that is that getting the ball does not matter, it is always a foul if you do not do so and sometimes a foul even if you do.
In this instance the fact Lindelof pokes the ball out from between Zaha's legs before any contact is made is incredibly important. If he had not done so it is, obviously, a penalty. The fact he did makes it very difficult for me to understand how you see this tackle as careless or reckless. Your wish to ignore that touch means you're trying to referee a completely different tackle to the one that was made.