The plugin’s description in repository says following:
Important caveat: this plugin currently has to be run on a linux server. Also, the wp-content/uploads folder has to be server-writable or it won’t be able to create the zips for backup.
…which makes me think that developer was not too interested in making plugin use proper WP APIs to work robustly across different hosting server configurations.
If this plugin alone generates enough debug output to break things I’d seriously consider looking for alternative.