Since everyone seems obsessed with placing blame so that they can label one pilot or another an idiot and then continue on with their own personal delusion that flying is very, very safe because they
are not an idiot, I'll make this proposal-
At this point we can say that the Cirrus pilot was an idiot and descended 150' too low. We can say the Robie pilot was an idiot and ascended 150' too high. The tower controller was an idiot for not being able to juggle a bunch of aircraft moving close to one another and give clearance instructions at the same time. The FAA are idiots for opening a tower and then handing it off to a contractor. The contractor is an idiot for only staffing one person in the tower to do all the chores. The neighbors of the airport are idiots for buying a house next to an airport, complaining about noise and forcing aircraft traffic into an idiot stacked pattern.
There are a lot of idiots at KFDK. If one wants to be safe flying, just avoid flying at KFDK.
Everybody feel better now?