why did Michael Jackson steal songwriting credit for "State of Shock"?

It appears that Michael Jackson stole songwriting credit from Freddie Mercury with the song "State of Shock." How was this allowed and why wasn't Freddie angry?

Freddie didn't write State of Shock - he never claimed to either

It was written by Michael Jackson and Randy Hansen
There was a (flase) rumour that Freddie used Ranhy Hansen as a pseudonom but, in reality, this isn't true

dammit I loved this story so much ! Are you sure ? And so, who is randy hansen really ? the guitar player born in 1954 ?