Welcome Shyspy. No yards is called against the kicking team not the receiving team. So there were no receivers to cover since they were on offence while faking/punting.
I can see why you think in this situation that it is unfair that no yards was called. This is of course a very rare situation, when a punter fakes then kicks anyway, but still it's generally much easier to give five yards than it appears. Sometimes players do get caught within the five yard zone because of a bad bounce or a situation like you described, but generally with some discipline it can be avoided. Keep in mind that other rules are in play as well. For example, the punter can recover his own kick (or any onside player for that matter, which in the case of a punt is nearly always only the kicker) so the receiving team can't just stand around the ball or the punter will get to it. So really both sides are under pressure. The kicking team (except the punter) must let the reveiving team field the ball by giving them space to do it, and the receiving team must field the ball quickly or risk losing it.
Sometimes players get caught, and in this case it's a five yard penalty. If the ball doesn't hit the ground first (ie. it is caught without bouncing) it is a 15 yard penalty.
It can also happen on a quick kick by the way. If a player boots it out of the end zone for example, it's quite possible that players not paying attention to where the ball is will get called for no yards.
So the point is you must be aware of where the ball is at all times. Otherwise, it could cost you. A fake punt punt is no excuse since the receiving team probably would get at least five yards if you had let them field the ball anyway.
The object is to allow the team to cleanly field and return the ball since there is no such thing as a "fair catch" (and probably never will be).
It's a drag for the punting team in this case that they got caught, but they did try to gain an advantage by faking then kicking. It backfired and cost them. Remember that it wasn't the punting team that had to cover down field receivers of a fake punt/pass, so they had no other responsibility than to let the other side field the ball.