A pitch clock violation can be committed by either a pitcher or a hitter. Both parties are subject to the new MLB rules being implemented for the 2023 season. If a hitter commits a violation, they're penalized. If a pitcher does, they're penalized.
The penalty for a pitch clock violation is either a ball or strike added to the count. If a pitcher is not set by eight seconds, they'll have a strike added to their count. If a pitcher misses the 15 or 20 second timer, they will have a ball added to their count.
This could result in the end of a plate appearance, whether by a walk or a strikeout. If it does so to end the bottom of the ninth, or walk in the winning run, the game ends. If a pitch clock penalty occurs to end the game, that's just how the game will end.
MLB pitch clock violation already ended a Spring Training game
The penalty for not meeting the pitch clock has been applied all throughout Spring Training, and it's even ended one game already. The same will happen throughout the regular season if players don't adhere.
The Boston Red Sox and Atlanta Braves experienced this. Cal Conley was up with the bases loaded and two outs in the bottom of the ninth. The count was full and he thought the pitch clock error had resulted in a free walk for him.
The umpire ruled that he was not set by the appropriate time and was called out due to that being the third strike. The rally ended and so did the game in a 6-6 tie.