Just standing around by the ephemeral nodes will readily out who is/isn't botting strictly due to their awkward movement patterns; particularly how they mount up and take flight before moving to the next node.

You also can often guess at who is/isn't a bot by simply glancing at the level-capped gatherers/crafters in player search and taking note of the ones that have only one DoW/M job at 90 with none of the others touched at all.