I came across this statementt in a "how to" cook a steak on a gas grill,
".... Then flip with tongs, not a fork. Don't poke any holes in your steaks at this stage because the liquids inside are under pressure from the high heat and you can lose valuable juices. By the way, those juices are myoglobin, a protein liquid found in the muscles, and they are not blood. Blood is drained during slaughter. Tell that to your squeamish teenagers."
It sure looks like blood!!!