How to exclude page from Redis cache?
Not sure how you are generating this dynamic page, but somewhere in the mix, you could put something along the lines of:

drupal_set_header('Cache-Control', 'public, max-age=0');       // set max age to 0
drupal_set_header('Expires', 'Sun, 18 Dec 1983 02:28:00 GMT'); // some date in the distant past


before any other output, eg, at the top/start of your page's menu callback or in right before you select its custom template if it has one.

If this doesn't work, a quick hack would be to do a drupal_set_message('Welcome to my dynamic page'); which would cause drupal's core functions to try not to cache the page :)