Walt Disney Co. (NYSE:DIS) shareholders should be concerned that 'Grey's Anatomy,' one of its biggest hits, jumped the shark last night.

Jump the shark is pop-culture slang indicating that a TV show has reached its peak. It derives from an episode of "Happy Days" in which Fonzie literally jumped over a shark on water skies while wearing his trademark leather jacket. The hit program just wasn't the same afterwords.

"Grey's Anatomy" didn't just jump the shark, it jumped the whole ocean with tearjerker of an episode in which the show's title character had a near-death experience after accidentally falling into the water. Somehow the effects of hypothermia didn't kill Meredith Grey and her heart started beating again after her best friend Christina Yang told everyone to take one more shot at reviving her. Of course, they did it and Grey pulled through just fine. Can anyone in the medical field tell me how often that happens in real life?

This blunder creates a problem for Disney's ABC network, which reportedly has plans to do a spin-off of the drama. The company wants to make Greys a tent pole franchise similar to the "Law and Order" and "CSI" shows which are cash-cows for General Electric Co.'s (NYSE:GE) and CBS Corp. (NYSE:CBS) respectively.

ABC may find that difficult to do. Once an audience gets turned off to a program, it's hard to convince them to go back. The advertisers know this and shift their spending accordingly.

What ABC is equivalent to McDonald's Corp. (NYSE:MCD) putting Cheez Whiz on the Quarter Pounder or Starbucks Co. (NASDAQ:SBUX) deciding to only play music from hair metal bands from the 1980s in its stores. The network tried to fix something that wasn't broke and will pay for it over the long term.

Like every network before it Walt Disney Co.'s (NYSE:DIS) ABC is trying to squeeze every nickle out of a hit show. Investors, though, shouldn't expect too much from the spin-off of "Grey's Anatomy."

Spin-offs have a mixed track record. General Electric Co.'s (NYSE:GE) NBC tried to capitalize on the success of "Friends" with "Joey", a mediocre sitcom that failed to excite audiences. The "CSI:Crime Scene Investigation" and "Law and Order" shows are successful because they have different casts. Of course, some of the most popular shows of all time were spin-offs including "The Jeffersons," "Mork and Mindy" and "Lou Grant" got their start from other shows.

But these shows are ancient history. These days, shows based on characters from other programs are rare, which is why ABC's bet on "Grey's Anatomy" is interesting.

The new show will feature Dr. Addison Montgomery-Shepherd, a popular "Grey's Anatomy" character played by Kate Walsh, The Wall Street Journal said. Basing a show on a flawed obstetrician is a good idea. ABC obviously is aware of the popularity of TLC's "A Baby Story." If it's good it will attract advertising dollars and give the network a profitable franchise.

But it's far from a slam dunk.

"Grey's Anatomy" came quite close last week to "jumping the shark" with its ridiculous two-part episode featuring a ferry crash. The main character Meredith Grey fell into the cold water after being rescued by McDreamy. Come on? Does anyone not think she's going to survive? I mean it's too late to change the name of the show.