Heres my
I recorded it , and listend to it many times, tweaked the eq and check the wav.
The last 10 seconds of audio on the tape is a least 3 different spliced pieces of audio. You can here it cut in, then 'mystery guy' speaks, then his last noise if briefly repeated, then he says the rest of what he says.
To me it sounded like an older African American male, and it sounded like he said:
"That will be enough...........that was enough." Thge the tape ends.
or more accuratly considering the skip in the audio:
That will be enough(.....nough)......that was enough."
It could be anything, probably something else. but this is what I heard.