Having worked in TV for the past three years I've come to a realization. People have this ingrained belief that local news broadcasts are no nonsense, serious places of business. With people working there that are equally 'no nonsense'.
So when something funny happens, someone makes a joke, its SO much funnier because 'that serious guy' said it.
Another thing I've noticed, when something scripted happens, most people will think it was an accident. I've seen so many Reddit posts of local new stations making obvious jokes and having them be misconstrued as 'mistakes'.
Or, when someone flubs on a word or sentence, everyone is always so quick to judge, just ignore the previous dozen's of minutes of flawless speech beforehand.
Local News gets a bad rap. These are hard working people that are human, just like you, they make mistakes just like anyone else, and they make jokes to liven up their workplace.