Are you sure the ladder point equivalences are not (0 ft, 0ns) and (20 ft, -8.8ns)?
It depends on which direction it's moving. I didn't bother to check the sign.
Thinking about it now, if it's going in the positive direction, then it should be (20 ft, -8.8ns). You are correct.
As per a recent comment this thread is meant to voice contrarian opinions, that is anything this community tends not to agree with. Thus I ask you to post your contrarian views and upvote anything you do not agree with based on personal beliefs. Spam and trolling still needs to be downvoted.