Respond with a citation to Ex Parte Brunson (Appeal 2009-012413 in U.S. application serial no. 11/387,179), which stands for the proposition that a per se rule (in this case "reversal of the essential working parts" is obvious) cannot substitute for a fact-specific analysis.
In Ex Parte Brunson, the Board reversed an Examiner's rejection of claims where the Examiner merely relied on the general rule of the "reversal of parts".
[w]hen determining whether a claim is obvious, an Examiner must make
“a searching comparison of the claimed invention - including all its
limitations - with the teachings of the prior art.” In re Ochiai, 71
F.3d 1565, 1572 (Fed. Cir. 1995). Reliance on per se rules of
obviousness that eliminate the need for fact-specific analysis of
claims and prior art is legally incorrect. Id. “Rejections on
obviousness grounds cannot be sustained by mere conclusory statements;
instead, there must be some articulated reasoning with some rational
underpinning to support the legal conclusion of obviousness.” In re
Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006), cited with approval in KSR
Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417-18 (2007).
The Examiner in your case is also making the impermissible inference of obviousness based on this same per se rule. A proper rejection under 103 needs a fact-specific analysis as directed by Ex Parte Brunson.
Just to be on the safe side, I would also traverse an implicit "official notice" by the Examiner.