Originally Ridley Scott was going to direct the film in the late-'70s, right after his debut film The Duellists (1977). He put the film aside to direct Alien (1979).
The poetry Isolde keeps quoting was written by John Donne, who was only born in 1572. The lines "My face in thine eye, thine in mine appears, And true plain hearts do in the faces rest; Whatever dies was not mixed equally; If our two loves be one, or, thou and I Love so alike that none do slacken, none can die." are from Donne's 'The Good-Morrow'.
At the party when Melot is trying to talk to Tristan and Marke about his choice for second, Melot says, "You don't seem to know what you've done here," but the motion of his lips doesn't match the words.
Isolde: Yesterday at the market, I saw a couple holding hands... and I realized we'll never do that. Never anything like it. No picnics or unguarded smiles. No rings. Just... stolen moments that leave too quickly.