I'd believe it. Rushed to the hospital on a Saturday night when my father in law suffered a massive heart attack... and he was held stable for almost 2 hours before a surgeon capable of working the situation was able to make it in and insert a stent. It seemed strange to me that a hospital would have a schedule like that... where most doctors work 9 to 5 monday to friday, and most everybody goes home for the weekends…
As another commenter below said, the ER is an entire business model on its own. The goal of an ER is to treat your acute illness or injury and then proceed to push you into a dedicated room to maintain stability. Most (unsourced) emergencies that come into the ER can very likely be stabilized by RN’s and consultation from a MD/DO. honestly, most orders in a setting like these tend to come from the bottom up (RN to MD for approval) if there is a trustworthy relationship between them. Depending on the severity of the patient, of course.
For an example, on 12/30 @ 2345hr, I got extreme abdomen pain and ended up in the ER. On 12/31 at 0200hr, the DO came in and palpated my stomach and concluded I had appendicitis. @ 0300 I was having a CT scan done. @ 0400 the DO was on the phone with the on-call general surgeon to consult with him about surgery for acute appendicitis which led to the eventual rupturing of my appendix. It was then at 1100 when I was in the operating room. Up until this point, every aspect of pain management (morphine every two hrs) and IV fluids were completed by a RN.
For my case, there was no need for a specialist to be on the clock. One was easily in reach but up until that next morning, I had no real need for them besides the one DO who came and put their hands on me as a formality prior to doing a CT scan. I’m mostly just thankful they have specialists to call to begin with.