IMHO whether or not the punt is blocked if the punting team recovers it on a spot on the field that did not get them past their yardage needed for a first down then it should not be a first down UNLESS there was a change in possession i.e. the receiving team had possession of the football and then fumbled. The kicking team should be trated as having gotten the ball to the spot where they recovered and went down. If that nets them a first down, then great; if that doesn't, then they didn't get the requisite yardage for a first down. Merely touching the ball doesn't amount to a change of possession in my mind. The receiving team never took over possession. I understand this means that a 4th and 1 is very different than a 4th and 20. Yeah, and it should be.
However I do agree with you gusy that refs called it correctly and the players ought to know the rules. Regardless, I think this is a bad rule. Along with countless others.