Some analytics packages have a heatmap feature that shows you where site visitors are hovering and clicking. That's a feature in CrazyEgg. It's a great feature for usability testing but it could be used to show if people are clicking on the triangles.
But what could you possibly do with the information? That's a rhetorical question. The answer of course is nothing. You could ban the site visitor by IP but that's easy to defeat and in any case the deed is already done. If you did create an "early warning system" to warn you about triangle clickers it would not change the fact that there is nothing you could do about something that's already happened.
If it's true that competitors do that then it's likely Google is already aware of false reports, particularly if reports are coming from IP addresses associated with spam.