Anon says it was a restaurant that happens to serve coffee; not a dedicated coffee shop. So, honestly, probably not. Chances are the coffee would be stale, burned, or just plain poorly brewed regardless of what beans were actually used.

A lot of whining is done about decaf, but it takes a pretty refined palate and a lot of experience consciously tasting the differences to be able to reliably tell the difference by taste alone.

The biggest giveaway is the near total lack of a caffeine buzz, even after several cups. But the placebo effect will go a long way to mitigate that.