Hi,
Having the integration with a lot of popular plugins, and also the ability to integrate invisible recaptcha into custom forms, It is going to be hard to detect pages where recaptcha is used. Can be in page contect, sidebars or even footers.
Yes, it is pretty easy not to render it into some specific pages instead of trying to detect if the script should be rendered or not.
If you need help to disable it on some specific pages just let me know.
~Mihai