Hi Steven, that is something worth sharing!
We use a checkbox field called "doesn't work at this company anymore". This is manually determined by our inside sales. Checking it results in two tasks. 1) updating/finding the new mail address, 2) Who replaced the person.
For me increasing leads score makes no sense, because at that point in time the lead is already handled by sales. But still something worth thinking about. It's exactly these kind of questions someone should ask themselves when creating a lead scoring startegy.