Objective Lens question

So I got this PVS-14 in a trade, tube is awesome and it looks great, however I was adjusting the objective lens and I heard the seal break and realized I was able to completely unthread it. It went right back in and everything is fine. But I’m not sure if that’s normal. I have zero issues with focus or image. Just don’t think that’s supposed to happen, should I send this to someone who knows what they’re doing? Thanks