The MRI technician reassured Dylan that, if he was concerned, there was a speaker inside the MRI machine. He meant microphone.
The M.E. (Doug) called the waxy substance on the decomposing head 'adipose'. This is an adjective meaning 'pertaining to (animal) fat' (as in adipose tissue). He meant 'adipocere'.
Dylan is suffering from undiagnosed intermittent vision problems, yet he still rides his motorcycle to the precinct house, as evidenced by him walking into the squad room carrying his helmet.