Until recently most type I diabetics used insulin from animals such as cows and pigs. Since you need insulin to survive if you are type I diabetic I assume that this was OK for vegans?
Starting in 2006 all insulin in the US is made by recombinant DNA techniques using E. coli bacteria. I suppose bacteria is an animal but once again I don’t think a type I diabetic can live without insulin so they don’t have much choice in the matter.
You are correct that a Type I diabetic needs insulin to live.
As to your larger question, I’m not sure exactly what you’re asking. There was no Food Police to bust a vegan for taking animal derived insulin. People had mixed opinions on the matter. Of course, most people view lifesaving medicine as an exception to moral veganism, but there are some who don’t.
There are some who try to make a vegan using insulin into a hypocrite for political reasons, even though the accuser themselves might not have been vegan. PETA Senior Vice President MaryBeth Sweetland has faced a lot of flak for using insulin. Sometimes it’s claimed her insulin has animal components (she’s confirmed this in interviews) and sometimes that it’s tested on animals, and the subtext is always that she’s a hypocrite for using lifesaving medicine which exploited animals in its creation while she heads PETA, a group dedicated to promoting extreme animal rights, including no medical testing on animals and veganism.