My guess is that the missing periods at paragraph breaks indicate he wrote this on an iDevice. Space-space: period added. Enter-enter: no period added.
Quick test on a text field in chrome on my Galaxy Nexus shows the same behavior listed above: two spaces automatically ends the sentence with a period, but two carriage returns does not.
He could have written this on any mobile computing platform.
That being said, he did use short hand texting "speech" with his "w/".