I was very turned off by his poor attitude towards me, so much so that I don't plan on returning. While they have a great vegan selection (including delicious "soft serve") and cool decor, I prefer to support restaurants with positive energy and sensitivity to customer's dietary preferences. According to an employee, the owner's attitude is a common complaint, and it occurred to me that he's hasn't been very pleasant in the past. Their saving grace is Ryan (the cashier), who has always greeted me with a warm welcome - I was sure to thank him for that before I left.
There are a lot of restaurants with vegan options in Santa Monica, the majority of which treat their customers with respect; I'll choose to go to one of them next time. However, I'm always willing to give someone another chance if they make the effort to be kind.