Casino security was originally tipped off that something was amiss when Eisenberg’s tips suddenly increased dramatically, from less than $200 per day to over $500.[pokernewsboy.com]

Even if surveillance didn't notice, his fellow dealers would have ratted him out, the employee chip bank (or wherever they convert their tokes to cash) attendant would have ratted him out, the poker players would have ratted him out ... sooner or later, you're going to get ratted out ...