Due to its vignette-heavy format and its Ninja Pirate Zombie Robot gamut of content, MW is roughly as common in pro wrestling as a tapout victory.
WWE's second annual Great American Bash, held in Buffalo, New York, in July of 2005, had no fewer than three instances of Mood Whiplash, and possibly four:
One of the most heavily promoted matches of the night was a Number One Contender's Match between The Undertaker and Muhammad Hassan that stemmed from Hassan's having run away from 'Taker during an earlier Number One Contender's Match. Hassan claimed that he was not afraid of Undertaker and that he was going to become WWE's first Arab-American world champion. Naturally, he was also at this time vehemently denouncing the United States and parading into arenas on a litter carried by several black-masked "sympathizers" before ululating like a muezzin, drawing tons of racially-charged ire from audiences. During the match at the Bash, Hassan's masked lackeys cheated on his behalf at every possible opportunity, even trying to choke out Undertaker with piano wire. After 'Taker finally managed to win the match, the lackeys attacked him in retaliation; the "Deadman" made short work of them before stalking Hassan to the entrance ramp and giving him a Last Ride through an exposed compartment of the stage, breaking every bone in his body and supposedly "killing" him.
After the Mexicools' victory, the mood was whipped right back to "dark" with a bitterly personal feud between Eddie Guerrero and Rey Mysterio over which of them would be granted custody of Rey's son Dominick. Eddie threatened to reveal a terrible secret if he beat Rey in their match (which we later learned was that Eddie had apparently fathered Dominick out of wedlock with a prostitute and then given the baby to Rey and his wife to raise as their own child). The mood leading into this match was about as somber as WWE could get, with a frightened Rey and Dominick praying and holding each other backstage and commentators Tazz and Michael Cole outright condemning Eddie's behavior - and then during the match, Eddie cruelly manipulated his opponent by using Dominick (who was seated at ringside) as a human shield). Luckily, Rey managed to win the match, so the nightmare was over....at least for a time.
Finally, Torrie and Candice's lip-lock was followed immediately by the arrival of Number One Contender John Bradshaw Layfield's motorcade - which, while not quite an example, was still quite jarring because it's hard to focus on an official-looking white limousine when you're still trying to push your boner down.
One of the weirdest examples would be The Miz's characterization. We know that he won the WWE title by cashing in the MITB case and then tried to become darker and more evil. However the very week before he did this, he cut a promo with...Peewee Herman, where he was beaten senseless in a match against the Big Show...who came down also dressed as Peewee Herman.
The May 14, 2012 edition of Raw saw an emotional segment with The Big Show being forced to his knees to apologize to John Lauranaitis or be fired. He did so and was fired anyway. With tears in his eyes, the 20-year veteran was stripped of his dignity and forced to walk away from the career he loved so much, as Jerry Lawler decried Lauranaitis's actions as abuse of power. Lawler's impassioned commentary was immediately followed by ... "The Funkasaurus" Brodus Clay.
TNA: During the Thanksgiving edition of Impact, M.E.M and Ken Anderson were mocking the death of the Aces and Eights faction after Anderson's victory over Bully Ray. When it seemed like everyone was having good times, one member came to the funeral: Bully Ray himself.
Bully Ray Ken, you raped me of everything, and for that I will never forgive you. You better sleep with one eye open. You better sleep with one eye open in the best interest of yourself, but for the best interest of your pregnant wife. You all look at death as the last sleep. I look at it as the final awakening...