The way I read it, basically yes. Except if you're the owner of the games being shared you get priority and the person you shared to will get kicked off in a few minutes if they are playing one of the games in the shared library:
"When I authorize a device to lend my library to others, do I limit my own ability to access and play my games?
As the lender, you may always access and play your games at any time. If you decide to start playing when a friend is already playing one of your games, he/she will be given a few minutes to either purchase the game or quit playing."
"When I authorize a device to lend my library to others, do I limit my own ability to access and play my games? As the lender, you may always access and play your games at any time. If you decide to start playing when a friend is already playing one of your games, he/she will be given a few minutes to either purchase the game or quit playing."