According to Autobiography it was something he overheard, I'm not sure if there's surviving footage of this news bit.
"Bundled into the venue, I momentarily pass by a special room set aside for press reporters, and I see one very stately black man in an impressive suit speaking directly to a news camera.
‘Morrissey conveys all the worst elements of homosexuality and bestiality,’ and I wonder if he could possibly mean me. It is not enough, I note, to represent homosexuality fused with bestiality, but indeed I apparently convey all the very worst elements of both."
However (and this is going off on a tangent...), it's worth keeping in mind that the chronology in this section is particularly shambolic.
For instance, he didn't play Santa Monica in 1992.
Before recounting his unpleasant encounter with that news reporter, he talks quite a bit about the crowd storming the stage during his appearance at Pauley Pavilion, UCLA three days earlier.
He also didn't play UCLA in 1992 and he definitely couldn't have been singing You're The One For Me, Fatty when the "riots" started in 1991 (when he actually did play there), because he hadn't even birthed this lyrical masterpiece yet.
Anyway, I'm rambling.
Here's the UCLA "riots" covered by the LA Times (in 1991! Not 1992)
On the day after 48 people were hurt in a sudden rush toward the stage at a Pauley Pavilion concert, UCLA officials and a concert promoter blamed English pop singer Morrissey for the melee, saying he should not have urged the audience to move in closer.
www.latimes.com
And here's a news bit mentioning some fans fainting after the Santa Monica show but no bestiality: