Not very convincing to me.
First, he did have 2 wins in senior 3.5 Men's. That may be enough to rate him at 3.5
Second, as countless people around here have said it over and over again, W/L does not matter. What matters is how many games the person won during those matches and the ratings of the person playing against him.
3-3 loss against a benchmarked 3.5 is going to register as a competitive 3.5 player. It does not matter if he plays the same guy 10 times and lose 10 times with similar margins.
If he is not competitive at all in 3.5, he will be bumped down.