And yeah, maybe making the ToS less confusing should be the way to go. Reading it again and again, I'm quite sure the 'at least minimum one bet 50% requirement' is across multiple bets. It said 'at least one bet', so meaning it can be multiple bets.
ToS shouldn't be 'more' or 'less' confusing but clear and unambiguous. There is always the possibility of manipulation or abuse by either party if the rules are not clearly defined.
I've never encountered such a rule at any casino before. As I see it, there are two possibilities: the rule is intentionally written vaguely so that it can be used against players in certain situations, or, more likely, the rule is erroneously worded and should be reformulated.
And I've never experienced any shenanigans from FJ. They've been a great bookie for me.
I'm fairly certain this is not an issue here. It would be really good for FJ to reformulate the rule or explain it in detail so that it doesn't lead to a wrong conclusion.