“Exhaustion”—for celebrities, it’s the all-purpose smokescreen, excusing everything from blabbering coke-overs and alcoholic stupors to bulimia-induced collapse.

But as The Smoking Gun reports, at least one Hollywood producer is calling bullshit on exhaustion—specifically, the alleged exhaustion of hard-partying starlet Lindsay Lohan.

In a letter delivered to the 20-year-old actress at the Chateau Marmont hotel earlier this week, the chief executive of Morgan Creek Productions blasts Lohan’s “discourteous, irresponsible and unprofessional” behavior during the filming of Georgia Rule, co-starring Jane Fonda and Felicity Huffman. Acknowledging Lohan’s claims of illness, Chief Executive James G. Robinson writes that he is “well aware that your ongoing all night heavy partying is the real reason for your so called ‘exhaustion.’”

To read the whole, actual letter sent to Ms. Lohan—who is threatened with legal action if she doesn’t clean up her act—go here.