ok the facts:
the name of the the producer/engineer the article is reffering to is TONY GUITERREZ.
u can see him talking about his recording session with 2pac on september 6th 1996 on the "2pac - genius" dvd.
that's what i remember him sayin:
2pac came into the recording studio (in los angeles, forgot the name of the studio but it's shown on the dvd) at around 4pm after shooting a music video.
the name of the music video is not mentioned but guess it was "toss it up" according to several sources including kc and jojo.
tony and his associates have rented the record studio the whole day to record a walk-in song for mike tyson's fight next day (against bruce seldon).
typical pac,he walked in and did "let's get it on" in less than an hour.
after pac asked the prodcers if that was all he had to do, he found out that they had the studio for the whole day.so he didn't waste an time and ordered the producers to do some more beats he can spit on.pac wrote the lyrics right on the spot from the top of his head.that's how they ended with a 2nd song (name of the song is not mentioned, but it's a 2pac solo).however pac was still to quick!
during the session the outlawz dropped in and pac urged them to spit some lyrics for a 3rd song.after that pac left to go home and pack for his trip to vegas.
so "let's get it on" is not 2pac's very last song, it's his 3rd last to be exact.
2pac's very,very last song is a collabo wit the outlawz.