To me the fundamental issue isn't whether or not the .gov can find a suitable scapegoat to throw under a bus, it's the fact that it could happen at all. The AP "investigation," in particular, seems to me to offer a demonstration of yet another increment in the inexorable march toward micro-parsing words while ignoring the intent
of the Constitution.
What does the 1st Amendment say?
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
In this case, the Congress did not "make a law," so a Bill Clinton "It depends on what the meaning of 'is' is" protege would argue that the 1st Amendment has not been violated. But if you take broad view that the intent of the 1st Amendment is to tell the government not to interfere with the press ... then it becomes obvious that we are not just approaching a slippery slope, we are on the toboggan and careening over the precipice at breakneck speed.
The same argument holds regarding the IRS using audits to stifle political dissent. The Congress didn't pass a law saying "Thou shalt not be a conservative," so on the literal level there's no Constitutional violation. On a wider, moral/ethical level, if the intent of the 1st Amendment was to protect political speech from government retribution, then the current government (regardless of who is sitting in the Casa Blanca) is perilously close to the point of no return.