Without a doubt.
Did the shop where the ring was purchased ask for a local address? That'd be a red flag right there.
Would have been easy enough for someone to follow you. Perhaps the shop has video of anyone else in the shop at the time of your purchase who left right after you? Or someone from the shop getting on the phone while/after you made your purchase?
Anyone else on-island know that you bought jewelry AND know you were out to dinner?
My first instinct was to have a similar reaction.
I am in the jewelry business, myself, and I do know of incidents here in the States, where jewelry store sales people have set up a customer, or a vendor for a theft, by alerting partners after they realize you might be a likely target.
It could be a random burglary of course, but the timing is really making me suspicious.