Sure, if you have a novel result, say from some experiment, you afterwards come up with theories to explain it. This is different from policy decisions though, where you have a situation at hand and need to come up with a way to deal with it.
In this case:
There's an epidemic, we need to contain it
-> it spreads through viruses expelled be sneezing
-> use a mask to hinder the spread
vs
People tell me to use masks, I don't like that
-> I need a reason to justify not wearing a mask
-> "I can't breathe!!"
Swastikas aren't outlawed outright, they're fine when displayed in a disapproving way, such as a crossed out swastika or a swastika being thrown in a bin.
This is a different case though, I'm not sure if he could have argued he used it to disapprove of the AfDs fascist policies and get away with it.