Here's the convoluted response I've heard...
"Jehovah knows how to read our hearts. If he sees that someone knowingly violates Bible principles regarding blood, that person will not survive Armageddon. On the other hand, if a JW consumes food without knowing that said food might have some blood, Jehovah will forgive that JW. "
So... It's OK to eat steak. Just pretend you don't know that it may contain some blood.