Our interpretation is that people who responded positively to these statements would feel they “win” by endorsing misinformation—doing so can show “the enemy” that it will not gain any ground over people’s views.

The article glosses over the distinction between endorsing misinformation and believing misinformation. I think people often interpret poll questions as expressions of political affiliation, so for example a person who thinks that the covid lockdowns were a mistake might say that covid is caused by 5G because that’s the answer that upsets or offends lockdown supporters, not because this person thinks it is the literal truth. In other words, what the authors are seeing is not necessarily sincere belief but rather a deliberate, politically motivated endorsement of statements known to be false.