When interrogating Sam, Detective Bird and Britton are seen writing notes on legal pads, however, when Detective Bird walks out of the house he no longer has the pad, while Detective Britton does.
The camshaft Hannah discovers is indeed a camshaft, just not for an engine small enough to fit a Triumph motorcycle. The camshaft she holds up is for a much larger engine - likely an American pushrod v8. The item she has is nearly ten times the size it should have been.
Early in the episode, the pathologist is talking to Britten in the dissection room. The cadaver lying between them on the table can be seen to be breathing.