But then again, Spike claims not to have smelled Angel's presence either (he used his vampiric eyeballs instead). Maybe the tomb smelled so strongly of age and dust and decay it blotted out everything else?

And maybe The First was standing outside handing out tickets. "Caleb, 11.30 to 11.35. Angel, 11.35 to 11.40. Spike, 11.40 to 11.45". :-)