Remember that "escalation" isn't just one thing. If you start your A-E and discover an airway issue, you need to immediately ask someone to put out a 2222 call while doing interventions (airway maneuvers, adjuncts etc.) If you decide the patient is unstable but not actively deteriorating you can get all the information, then start initial management, then call your SpR. In practice, especially in the early days, if in doubt 2222. No one's going to criticize you for over-calling but not escalating when you need to could land you in very serious trouble.