Whenever a critique starts with "plot holes you could drive a (big thing) thru", I wince. And then maybe cringe. There may be a heartfelt sigh thrown in.
It's nearly certain the person making the challenge loses credibility in at least one of three ways:
1) Sharp and spikey ignorance of some facet of our world.
"They're based in New York and over the commercial break, they're suddenly in Boston! Sneer! How?"
"They took an airplane."
"An airplane. A flying machine people use to travel."
"Well, I never heard of an 'airplane'? How do they expect the average viewer to know such crazy things?"
2) Not actually paying attention to the plot.
"She picked up the phone and called the mayor directly. That's just silly!"
"She's the mayor's daughter."
"What? When did they reveal that?"
"In the first episode."
"Well, they shouldn't be so obscure and make it clearer."
3) They really don't like the show, so are in no mood for granting leeway.
"How did they get across the city so fast in gridlock traffic? That's story-breaking unrealistic!"
"The cop show you never miss does that every episode."
"Yeah, well...the cop on that show is cute. This guy is ugly and has a funny moustache."
If all three of these situations can be honestly said not to apply, then we can talk “plot holes”.
(Amendment Clause: Innocent confusion may prevail in some instances. The original production might have had explanations of “airplanes” or “mayor’s daughters”, but we only saw the episode after some greedy editing job removed that scene in order to show us dancing rabbits selling toilet paper.)