Again, this is a person who was diagnosed later in life, so the disease progression is likely to be slower than in a child for example. The fact that they eat extremely low carbs is relevant and is no doubt helping the pancreas by needing it to produce less insulin.
For me, as a diet controlled T2, the level of carbs I have varies from 50-100g generally. I would not want to go lower than that for any great length of time as I don't enjoy very low carb eating. My bowel doesn't like it either. We need to remember we are complex beings, not just diabetics. Other health conditions come into play too.
For me, when the time comes that 50g carbs is too high for my body to cope without insulin, I will choose insulin over making my life miserable by trying to exist on a strict diet that neither me or my body likes.
I think the idea that T1s always need insulin right away came from a time where T1s were nearly always diagnosed as children or young adults and where diagnosis was made at an urgent, life threatening stage.
Many on here have talked about the T1 honeymoon phase which can give some grace period allowing a person to have lower exogenous insulin needs, but it isn't always helpful as the pancreas isn't always consistent in its output of insulin. So in these cases low carb can help level out some of the inconsistencies.