The mouth is full of nasty bacteria, which live there harmlessly, but can cause life-threatening infections if they burrow into tissue (see Differences Among Germs. If you want to Google image an impressive example, try “Ludwig Angina”. It’s very rare. Symptoms are not at all subtle. Immediate antibiotic treatment can be life-saving, surgery may be necessary.
If a patient with sore throat so sick they’re drooling, neck bent forward, we never examine the throat. They might have Epiglottitis (infection of the epiglottis, see Diagram — Upper Respiratory Tract). If so, the least little gag might cause spasm of the trachea (tube to the lungs), cutting off air & causing death.