4 matches is hardly enough of a sample size to determine that he belongs at 4.5
He very well may have had some very good matches, and his opponents could very well have had some bad matches ... it happens.
My friend who just got bumped to 4.0 for 2012 went 19-2 in the spirng season and was bumped to 4.5 for 2013. He had a reasonable sample size of matches to determine he was ready to move up .... 4 matches is really not enough, especially when they were all close scores.
I know people who were bumped with very matches. A former team mate went 3-3 and was bumped to 4.5. His losses were 1-6, 2-6, 3-6, 4-6, 4-6, 1,6. Unfortunately one of his wins was a lopsided win against a ringer who threw the match against him. Completely unfair that he was bumped. He basically quit USTA after that.
Another guy was bumped to 4.5T after winning a a 4.0 tourney playing only 3 matches.