L i N d $ @ y

That's why I'm assuming that while he was obliviated and forgot what happened in NYC, the spell wore off and he was able to remember everything eventually. I do think that's a problem because what if Jacob was just some random person and is not friends with Newt? Then that means he'll remember magic. Although the Thunderbird was able to make most of NY forget magic so in that regard Jacob is safe because it was only Queenie who put a spell on him.