No, but I think I've seen the clip with the kiss itself. I'm pretty sure they showed it in the film version of The Celluloid Closet, a documentary on the history of Hollywood's representation (such as it was for many decades) of lesbigay people, and which was narrated by Lily Tomlin. The kiss was very aggressive, with strong overtones of self-loathing and contempt for the man being kissed.
I saw "The Sergeant" many years ago and from what I remember, Steiger played an overtly butch, outwardly appearingly heterosexual man's man, with a hidden secret self. The film specifically centres on a crush he has on a handsome young recruit. The climax of the film sees Steiger forcing himself on the young chap. From what I remember, the kiss comes across as part of what appears to be almost a rape sequence, not a loving encounter. This wasn't such an unusual depiction of gays at the time, who were seen as self-loathing perverts, obsessed with sex.
The reason the kiss in "Sunday, Bloody Sunday" came across as so staggeringly shocking at the time was because it was presented as part of a normal, loving, sexual union between two men. The scene was brilliantly shot in the garden of the Finch doctor character's sumptuously beautiful London home, with Mozart's opera "Così fan Tutte" playing sublimely in the background (I later purchased the recording!). Murray Head enters nonchalantly and suddenly, as they greet each other, quite unexpectedly, their heads fill the screen in profile, in a huge close up, in a passionate French kiss. I saw it at a packed, suburban cinema in Sydney with my partner, and there was an audible "Gasp!" from the audience - including us!
