First off, if people are being arrested and not charged, that's a violation of their rights, and a huge hassle. If your law is written so that people are being unnecessarily arrested, that's a bad law.
Proving intention used to be the case, but I think a lot of speech laws being made aren't taking this into account, and this is incredibly dangerous. You used the words "gypped" or "scot-free"? Well, those terms are an implied racial (cultural really) slur.
"Hocus pocus" originally comes from Protestant mockery of the Latin words of Consecration from the Catholic Mass. Catholics could, in theory, be offended by that. (I'm Catholic, but I just see it as an interesting piece of historical linguistic trivia, although I know it wasn't always so).
You used the words or "niggardly" or "snigger"? Neither of which have any negative racial or cultural connotations. The first is of Scandanavian etymology, and the second is of Dutch etymology, but they sound a lot like a word that is insulting. If someone takes offense at your racial insult, when you were using a perfectly innocent word, can you use that as a defense? Will it matter when social media has already tried and executed you, and are marching for your punishment?
People are being arrested for using the wrong pronouns. There's no way it can matter whether that was intentional or not. Hate speech laws are defined based not on what someone does, but on how someone else reacts to it, and it's impossible to list all the ways it could be applied. For all we know, people can get into trouble for something that started out as a 4chan prank.
There's no way to prove it one way or another. Proving intention to murder or conspire can be made using physical evidence, but how can you prove you were doing it with or without malice aforethought?
Were you warned and then persisted in your behavior? OK, maybe that would count, but it could still be a slip of the tongue or a typo. This is about as Orwellian as it gets.
That's why hate speech laws, even the best intentioned, scare the crap out of me, not because I support hate-speech, or use it, but because I know that it's way to easy to turn them into a witchhunt, and to prosecute people for completely benign behavior.