This is good, but there would also be cases where you might have a one game lead for example with someone with one game left but you have a better PD than them by 200 points or so and It won't say you are clinched because technically they could still catchup to you if they win and you lose by a combined 201 PD difference, when in reality this would never happen. How would this work in with PD?
If the fourth place team has a one game lead with +999 PD on the fifth place team, they play the last game of the season, and the fourth place team forfeits, they don't make the playoffs. Clinch means clinch, not "You're in unless you do something stupid."