Can you believe an inmate sued the federal government for negligence that allowed him to escape from jail?

Sure why not. America is the land of lawsuits like hot coffee!

Can you believe a lawyer had the nerve to file the suit?

Yes. This is common ( according to TV). As a defendant, you want to slander the prosecutions ability whether it is negligence or not following procedure, to open up your past case to give you cause for a retrial. Incompetence is an accusation you could levy on both the federal government or the prosecutors. In this case, the escapee wants to have his additional sentenced reduced to nothing for attempting to escape. He is not going to get $10 million in damages because he did not suffer $10 million worth of damages. Best case, he gets his medical treatment paid for and no sentence. Worse case, he gets an extra two years.