Final answer:
The least anticipated ECG finding in a patient experiencing an acute myocardial infarction is the Osborn wave.
Step-by-step explanation:
In a patient experiencing an acute myocardial infarction (MI), the least anticipated ECG finding would be an Osborn wave. This characteristic waveform, also known as a J wave, is typically seen in hypothermia and certain other conditions, but not commonly associated with MI.