However, the claim that the market cannot be manipulated is highly dubious.

And of course I didn't make that claim. From the article:

I won't go so far as to say that gas and oil prices can't be manipulated. OPEC as a group can manipulate prices if they still have a couple million barrels of spare capacity.

Also, while I know that you believe speculation played a very big role in recent price run-ups, many here do not believe that. If they don't believe that speculation ran the price up, it's kind of hard to accept that it ran the price down as the speculators unloaded their positions (not my position, but in essence the position of many posters here).

It seems that the administration can have at least as much impact on oil price as OPEC.

Just count the number of times the administration threatened to bomb Iran, and the number of carrier battle groups in the area, this year vs. the previous two years.

By ceasing the saber rattling they can impact oil futures without conspiracies or other machinations.