If those files he gave you are inside a VIDEO_TS folder and have .vob as suffix (plus some .ifo and .bup files) and it plays back in Mac OS X' DVD Player, then yes, those files are now in Standard Definition (SD) and only a quarter of its original resolution (if the source was 1080p/i).
You should get the original HD files of the finished sequence in at least the format he edited in (depending on the application he used) and a compressed .mov or .mp4 file using the H.264 or x.264 codec.
May I know, how much you know, about video editing and all the formats involved in editing and distribution, just so we are on the same level?
And is that guy a professional video editor / camera man or something else?