I know I should be telling you of all people lol but this is DAYS and the cops well you know haha if they find anything it's because the writers get smart for a few seconds and that was THAT.The thing is, Nicole saw that ring, and what Deimos said about it. So obviously, she has not yet noticed it on Kate's finger. and yes, I can see that when/if she does......it would be major!
But also am guessing Kate may have edited that part out, or maybe had not yet begun filming. However, if she did edit it out, Roman can take her phone, and they will find it.