Any rider to win title while out hurt?

Tomac in 2023 sx

You mean something like, the points leader is out for the last round and 2nd place just needs to go 1-1 to get the title but they fall short? It's a great question! I'd love to know.

No one other than Tomac recently.
 

I think it was 2010 and Pourcel had a 9 point lead and crashed in the second moto at the last round and Trey Canard wound up winning the title that day. 

Villopoto in 2011 sx ?  (I may have the wrong year).  One of his sx titles he wrapped up early then wrecked his knee.  

Herlings in 2013, broke his shoulder blade right after winning the world title

No that would have been if, after Tomac was injured, Chase somehow choked and didn’t get enough points to overtake Tomac.

It seems most people responding are not understanding the question.

Mark Barnett 1980 125 outdoor title, had won every moto going up to the last round. Broke his collarbone practicing during the week before last race. Won the title and did race last round. 

Darryl Schultz checked out of the hospital to gain enough points to keep it from happening 

It’s Vital.

It was 2012, got injured at Seattle.

OP,

If you are asking have guys ever choked with the chance to win the title with competitor injured. Not sure on that. 

Jochen Rindt won the 1970 F1 World Championship despite dying in Practice at Monza (with 4 rounds left).

In fairness, it takes a moment to suss out the question.

On the champs not at the final round angle, Hannah either was allowing his wrist to recover or just didn't race the last two nationals after he clinched in 1978 (rumor was that he wasn't going to race because he would not have made any more money than he already had by clinching, which sounds plausible for that era but may be apocryphal).

So in the lead before the final round but hasn't locked up the championship. Get's hurt, can't race - "out hurt" per OP not racing hurt. Competitor can mathematically win the championship but doesn't. 

Can't think of any in moto.

Webb this year would be the closest to that scenario I would think

The closest thing I can really think of was 2008 SX when Reed got hurt. Don't think he missed any rounds, but he did use his provisional to get into the main and rode with a broken shoulder blade or something like that. 

Something kind of similar in the NFL in 2004.  The Buffalo Bills just had to beat the Pittsburgh Steelers in the final game of the season to make the playoffs.  The Steelers were good, but had already clinched the #1 seed, so rested many of their best players.

Meaning all the Bills had to do was beat the Steelers' backup players and they make the playoffs.  They lost 29-24.

Weird foreshadowing of the crash itself too. Francois Cevert had an insane crash (in the same spot) going over 100+ / flipping, etc. was fine & joking about it with his friends back at the truck. The next day, Jochen crashed right in front of him (going ~80) & died. The severity of everything hit him like a brick wall. Fast Forward to the Glen in '73, Francois (of whom was about to replace his mentor Jackie Stewart & get his Championship winning seat for '74) unfortunately ripped through a guardrail going over 200+km/h.

Two more random sad facts that added to the heartbreak of the moment, were: 1. it was Jochen's Wife that was the de-facto head of the "Doghouse Gang". the Wives of the Drivers & Team Members basically started a Union that's main purpose was to raise money for the family's of the Driver after one of them died. For reference, Jochen was the 3rd Driver in 12 months to die in F1. 2. at the time, Jochen was the 4th Driver to Die racing for Colin Chapman in a decade! The Brilliant Lotus Founder went through it as a Team Principal / Owner. Lost his Best Friend / Brother Jim Clark, then 2 years later loses Jochen, then Graham Hill's death, Francois' death (didn't drive for Lotus, but was like Senna's death), etc. it was Ronnie Peterson's death in '79 (also at Monza, like Jochen) that pretty much (paired with the DeLorean situation) put him over the edge. He ended up dying in his early 50's a few years after Ronnie's crash.

A fun fact to end on though, & even circle it back to Moto!, if it weren't for Jochen Rindt - Red Bull Racing / Motorsports wouldn't exist.

I don't think Rindt celebrated at all.

Mike Kiedrowski ‘93.

Mitch Payton won his championship the season he got hurt.