Serious question: How do you avoid being blamed after all? I've observed reactions like, "It looks like you are just incompetent." and, "Whatever, just find a solution."
at least that's what i hope i'd do. it's never gone that far for me and in practice i'm only ~80% sure that i wouldn't just tell them to choke on a dick and get myself fired at that point. to be honest if you have a boss like that you should be spending all of your time and effort on finding a new job rather than trying to solve problems at your current one anyway.