The problem of who you prosecute when it's unclear which of a group actually did it is why English common law has "Joint Enterprise". [Whether this is sometimes abused is a different question]
If the Crown can convince the jury that you were one of a group of people with some common criminal purpose (e.g. scare a family into not going to the cops, rob a jewellery store, break someone out of prison) and that some specific crime was committed by someone in the group and that a reasonable person could have foreseen that this might happen in the course of the purpose based on what you knew, then you are guilty of the specific crime under this "Joint Enterprise" doctrine even though the jury weren't convinced, and may never have been shown evidence, that you did it and you claim only to have intended the broader crime, likely with a much lower tariff (e.g. murder usually means a long prison stretch, robbery not so much)
I think the parent was making a coy reference to the TV show Arrested Development, how it has a couple with the confused belief that the state can't prosecute both a husband and wife for the same crime[1].
In any case, in the US, the analogous legal structure for prosecuting such enterprise crimes is generally RICO:
[1] which I always read as those characters getting the wires crossed between double jeopardy (you can't re-prosecute someone for the same criminal act) and marital privilege (you get some level of protection from prosecution when you're married since spouses can't be forced to testify against each other). In the show, their attorney really does suck and they make excuses for him.
My understanding is that RICO is intended to allow them to go after the guy behind the crew, rather than crew members, whereas Joint Enterprise is intended to allow them to convict the whole crew when a crime can't be pinned on specific individual members (e.g. because they wore masks; or they all stay silent and won't rat on who actually did it)
RICO means you can prosecute the godfather when his enforcers beat up store owners that owed him money, Joint Enterprise means you can convict all three armed bank robbers of murder even though you can't prove which of them shot the bank manager in the head when she was too slow opening the safe.
If the Crown can convince the jury that you were one of a group of people with some common criminal purpose (e.g. scare a family into not going to the cops, rob a jewellery store, break someone out of prison) and that some specific crime was committed by someone in the group and that a reasonable person could have foreseen that this might happen in the course of the purpose based on what you knew, then you are guilty of the specific crime under this "Joint Enterprise" doctrine even though the jury weren't convinced, and may never have been shown evidence, that you did it and you claim only to have intended the broader crime, likely with a much lower tariff (e.g. murder usually means a long prison stretch, robbery not so much)