I see what you mean. It is actually very difficult to talk about correct punctuation when the sentence stands in isolation. The fact that many of these examples are common in informal writing styles, while style guides suggest they are best avoided in formal prose, complicates the issue even more.
I think the best thing is to do is modify the rule so that it excludes ‘that’ when it is used as a pronoun, or at least with conjugations of ‘to be’.
For easy reference I have isolated, the occurrences of ‘that’ in the report and you can see such a change will take out the vast majority of hits. Late today, I will see about isolating the other errors, and how they relate to the problem.
That won’t happen
That’s the stupidest thing I’ve ever said.
That is somewhat explained at the end.
That is intriguing.
That wasn’t my intention.
That was the best day of my life.
That’s the absolute truth.
That way I kill two birds with one stone.
That sounds interesting. What did you tell her?
That’s the thing about people who think they hate computers. What they really hate is lousy programmers.
That’s the snag.
That is rather unexpected.
That was probably what influenced their decision.
That was an evil bunny.
That’s very sweet of you.
You’ve got it in one. That’s right.
That person may find another person willing to donate a substantial sum.
That is no business of yours.
Your opinion is off the mark. That’s plain to anyone.
That part of the brain is called the posterior superior temporal cortex (pSTC).
That you don’t believe me is a great pity.
That was well worth the trouble.
That sort of thing can happen when you are in haste.
That church on the hill is very old.
That was a close call.
That which is easily acquired is easily lost.
That Art Thou (1945)
That Art Thou II (1945)
That won’t change anything.
That’s Tom’s house with the red roof.
That boy who is speaking English is taller than I.
That’s something like a movie scenario.
That’s a class act.
That might be the most painful experience in my life.
That’s the kind of person I want you to become.
That’s just a shot in the dark. How do you think you’ll succeed by just acting on…
That’ll do you no good.
That which is evil is soon learned.
That’s the part I liked best.
That would be lovely.
That prediction was claimed confirmed by observations made by a British expedition led by Sir Arthur Eddington during the solar eclipse of 29 May 1919.
That’s too much.
That’s my name.
That’s about it.
That is well said.
That very tune reminded me of my adolescence.
That’s fairly reasonable.
That is not my idea of him.
That’s the way the ball bounces.
That’s a little out of focus.
That last comment was pushing it.
That’s how I feel.
That’s creepy.