Double dates rarely work out because your friend's girlfriend is scouring her single friends for someone (but can wind up causing arguments between friends).
Blind dates are tough unless the girl or your friend have a keen sense of what types attract each other. Some people can spot two strangers in a room at a house party and position them with the things they know about each other, or they wind up finding each other... sometimes they need someone to kickstart the conversation.
The 'he's single/she's single, let's hook them up' fails because there's nothing to talk about, not much attraction. It's pulling favors.
Women love playing matchmaker... usually self-serving.
Thinking that "you're not my type" equals "unattractive"... maybe she thinks like that, but that doesn't mean everyone thinks like that. I think she was resistant to going, and found an excuse to leave.
I would've said to your friend's
gf "Thanks for trying, but don't you think that was rude towards you to just walk in, size a friend up and down in 5 seconds, then bail? If that's how she is, no offense, but thank God she left." Odds are likely she's hooking up online.