Absolutely do not follow this advice. The OP is an employee or contractor for a CMG, not the hospital. As such, they should not be inserting themselves into the hospital operations or trying to shut down any portion of the hospitals property. If the OP tells the charge nurse to to do this and they comply, the OP will have a giant EMTALA target on their back for any patient who presents to the hospital for a MSE and is then turned away - especially in that last hour when the OP is contractually obligated to perform MSEs.
At the very least, the OP should remain on the property, performing MSEs to anyone who arrives, and providing stabilizing care during their entire shift. Absolutely do not tell hospital employees to shut down anything unless you want to spend the rest of your life waiting tables. What happens after the shift is highly dependent on what is in their employment contract and the steps that were taken to provide reasonable accommodations to insure patient safety. If the OP simply walks out of the hospital 1 minute after their shift ends without handing off their patients, they should expect to get a call from the state medical board regarding patient abandonment and CMS investigators for failing to stabilize any patient still in the ED with an EMC. On the other hand, if they document efforts to insure safe handoff to hospital providers, then the risk of adverse action from regulatory bodies is mitigated. I say mitigated, but not zero.
Finally, anytime a facility is left without coverage there is a ton of liability for anyone involved - hospitals, administrators, doctors, nurses, etc. Keep in mind that CMS investigators and state medical boards will not give 2 ****s about the OP’s pay. That CMS investigator will have no compunction about crawling so far up a doctors ass that a bronchoscope will be needed to pull them out. They will be looking to see if a provider met their obligations under the provisions of their medical license and EMTALA. While it’s important to be fairly compensated for the extra work caused by these situation, affected EPs would be wise to spend the same effort appearing reasonable and focused on patient safety when these situations arise. Otherwise, expect to pay all that over time in legal fees defending their ability to practice medicine.