C3 repaired: the boundary identity and its orientation

Integrated-action equivalence is unaffected. For compactly supported $h$, $\int {\partial }_{\mu }{B}^{\mu }=0$ with either sign, so $S_{\mathrm{EH}}=-(2/{\kappa }^2)\int L_{\Gamma \Gamma }$ and ${\ell }_k=-2[{\epsilon }^k]L_{\Gamma \Gamma }$ are unchanged. The error concerned the stated local identity, not the action.