The desk whom he was selling

Recently I was proofreading a friend's manuscript -- one in which elephants loom large -- when I noticed that Microsoft Word didn't like her habit of using who and whom to refer to the animals. These were elephants with names, though, and lots of publications allow who and whom for individual named animals. I wondered what the Word rule was, so I clicked on the wavy line.

Of course, I wasn't surprised to find the oft-misinformed Word telling us to restrict the use of that to nonhuman referents. (It's a myth that people can't be that, but it's one that many have embraced in our psychobabbling era, claiming that that is "dehumanizing.")

The usage examples, on the other hand, were a hilarious surprise. Here's the grammar checker's entry:

"Who", "That" or "Which"

Generally, use "who" or "whom" to refer to people. Use "that" or "which" to refer to anything non-human.

Instead of: She bought the desk, whom he was selling.

Consider: She bought the desk, which he was selling.

Instead of: They saw the play who got good reviews.

Consider: They saw the play that got good reviews.

Could this be the honest effort of a non-native speaker, or is it evidence of a sly sense of humor lurking behind the grammar checker's sober exterior? And are there other entries with equally subversive usage "explanations"? That would be the best surprise of all.