As far as I know at that time I wasn't having highs, just nocturnal hypos after too much alcohol. I'm afraid I did go through a rather heavy drinking phase, but no more! With the symptoms I was getting I was more afraid of heart disease, but that's been okay so far. Maybe your friend should ask the doctor straight out if it could be a hypo and get him/her to discuss it? Maybe the doctor doesn't know that non-diabetics get hypos? They can't know everything.
I used to have my blood glucose tested regularly - at least once a year - because I've been a prime candidate for Type 2 for at least 12 years, if you go by the book re obesity, but I only went out of 'normal' range last April, during the most horrendous house move I've ever done! Went straight back on low carb, got back into the NICE guideline range, then went on metformin to see if it would help the weight loss.
I don't think you necessarily have to swing back too high after a hypo.