Meh it didn't work out that way for Brock.
But it DID work that way for Brock's opponent, Shane Carwin. His last opponent was also Frank Mir, so one of them was guaranteed to "get around" the curse.
I know you tried to say it in your post, but it really wasn't clear, so i'm spelling it out.
Anyway, the stats:
Mir has lost 6 times.
Ian Freeman beat Mir, then
lost to Arlovski in his next fight.
Marcio Cruz beat Mir, then
lost two straight, to Monson and Arlovski.
Brandon Vera beat Mir, then
lost two straight, to Timmeh and Werdum.
Brock Lesnar and Shane Carwin beat Mir, then fought each other. Brock
won, and Carwin
lost.
------Carwin lost two straight, to Lesnar and Dos Santos
------Lesnar lost his next two fights after the "push," to Velasquez and Overeem.
Junior Dos Santos beat Mir, then
lost to Cain Velasquez this past weekend.
5 losses, and the one win came in a fight where both fighters had just beaten Mir. Only the first fighter (Freeman), avoided losing two straight, though Dos Santos hasn't fought twice since beating Mir.
Verdict: 5 out of 6 is a coincidence. If it happens 3 more times at least, it can become a curse.