How much does a medical transcriptionist edit dictations?

There can be various degrees of editing involved:

Physician dictates: No tenderness present over chest
Transcribed: No tenderness is present over the chest.

Physician dictates: Came in with chest pain
Transcribed: The patient came in with chest pain.

. . . I was instructed to type exactly what the physician dictated. I only changed or edited sentences such as when doctor dictates throughout the report he or she performed surgery on the left leg, and then suddenly changed it over to the right leg before the report was finished. And when I made such a change, I carefully read previous dictations and diagnosis of patient to be certain which leg the doctor actually performed surgery upon!