Sorry.
I'm not wrong.
Quoted from Encyclopedia Metallica.com
16.04.83
Having done his audition for Metallica, Kirk was accepted into the band; on this day he did his first gig with them in New Jersey. Exodus, Kirk's previous band, went on to release some good thrash albums in the 80's and early 90's.
May 1983
They went into the studio to record their first album, Kill 'Em All , produced by Paul Curcio. Originally, this album was to be called "Metal Up Your Ass", but the record distributors refused to release an album with such a name. The name was immediately changed to Kill 'Em All , in reference to the record industry's distributors.
and quoted from wiki
After Mustaine's departure, Metallica recruited Kirk Hammett, Exodus guitarist and one-time student of guitar legend Joe Satriani, whisking him into the studio barely a month after joining to record the album.
So hmmmm...............