This is already how the system works. If the CA CA goes off, it is not just audible, both aircraft involved get a red CA (conflict alert) next to their data tag. The CA CA goes off all the time when visual separation is being applied. It is part of the aviation social contract, controller points out traffic, pilot says they have the traffic in sight, controller assumes the pilot does in fact have the traffic in sight. This controller did it twice. I could not say I would have done anything different, except maybe not using "no delay" and "immediate" in the same transmission to the AAL departure, but I digress. The gist of it is I would probably not have done anything different if I were the tower controller. I feel really bad for him and his family because the system failed him as well.