Missed your snarky response when it was on page 1. It could actually be a lot more clear, and to me it seems 99.9% likely you are wrong. Unless you have actually tried accessing this club using a PC card while not flying a *A international itinerary and got in.
The page you linked to says that there are circumstances under which PC members have access to the LH Business lounge in DTW. (That is why there is a blue dot there.) But the general conditions for PC members must still apply. You are ignoring the small print at the top of the page saying
Customers must be ticketed on a Continental flight to gain access to international affiliated lounges. Now, I realize DTW is not international for CO, but I'm sure this exception is intended to cover this case. You are also ignoring the general PC member lounge access conditions I linked to in my previous post.
The CO access is through *A lounge reciprocity, so it should be the same as for RCC members unless CO has a special deal with LH or with this lounge. RCC members would not get access if not flying *A internationally ('Reciprocal club privileges extended to United Red Carpet Club members at U.S. Airways Club® when traveling on domestic U.S. Airways flights, and at the lounges of Star Alliance® member airlines when traveling internationally on those carriers' says the pre-CO in *A page at
http://www.united.com/page/article/1...ccMoreFeatures).
So, in summary, your argument is based on the absence of a little footnote for Detroit on a long listing of lounges that clearly wasn't designed around the highly special case of *A lounges operated by airlines other than US, UA, ans CO within the USA. On the other hand, there are lots of indications that PC members do not get access to *A lounges in general unless flying a *A carrier. Unless you have tried it, I don't believe you are right. I hope you are right, but I don't think so.