Regurgitation of stomach contents prompts the mouth to open widely, allowing the contents, whether liquid or "chunky" to flow unimpeded from the throat and mouth.
The act of opening the mouth also prompts the closure of the airway, therefore lessening the chance of aspiration of the regurgitated liquid or "chunks".
Not a fool proof method, but workable, if one is able to spontaneously open one's mouth while regurgitating.
Being restricted in opening one's mouth can prompt a "panic" gasp, which will cause the aspiration of whatever is in the mouth, leading to asphixiation, and if one survives the asphixiation, to a respiratory complication and even pneumonia.
So therefore, one can now understand the need for the wire cutters.
One can also see the need to prepare for the complications presented by carrying such implements upon an aircraft, particularly during these times of hysterical, uh, er, heightened security measures.