Mar is the principal author of this bill. This fact is widely documented. These news articles from PhilStar and GMA News, for example, date from 2008. Both cite Mar as the principal author of Republic Act No. 9504.
Why isn’t Mar’s signature on the committee report? Simple: he was on official travel at the time of filing on May 19, 2008. For reference, here is page 2 of Journal No. 78 of the 14th Congress.