Well I weighed well over 100kg when I gave birth to my second DD1 (planned CS) and it took next to no time for the REGISTRAR anaesthetist to get my spinal in. I've had vaccinations that've taken longer. I'm tall and obviously carry my weight well since the only time I was weighed during my entire PG was when they weighed me to calculate dosage (pre-op). They didn't blink an eyelid and it was soooo not an issue.

So I'd say this guy just has a high opinion of himself and the godliness of his interventionist medical practices, rather than any substantive reason for this suggested practice. Essentially he's saying that he finds it difficult to deal with a challenging anaesthetic when time is of the essence - or maybe he doesn't like getting called out in the middle of the night to deal with difficult situations that are beyond the skills of more junior staff.