And I'm wrong; it's Lynn using Mike as a mouthpiece for why she thinks training dogs is doomed to failure.
Panel 1: We start off with new-ruin Mike and Lawrence walking Farley. Mike yells "Walk, Farley! Walk!" Lawrence asks him "Aren't you supposed to say 'Heel?"
Panel 2: Mike, remembering what happened the last time he did that, says that Farley just runs when he does that. He thinks it's because the command 'Heel' doesn't make sense. This, of course, is because he and his creator think that Farley understands English and is confused by the odd word.
Panel 3: Lawrence then goes on to say "So he doesn't sit when you say 'Sit' or stay when you say 'Stay'?"
Panel 4: As we see Farley sniff a tree, Mike says no, he doesn't do either thing but he does smell things when he says 'Smell'.
Panel 5: Lawrence uses the verb 'smell' in its other sense when he agrees with Mike because Farley stinks.
Summary: Since John was the only person that really participated in Farley's training, it's not a surprise that he doesn't obey Mike; it's also not a surprise that Lynn can't see that.
ETA: In the latest banner, we see Mike, Lawrence and Gordo's relaxed, serious side. Coincidence? No! It's calculated image construction.