At first, Satan is enraged and prepares to unleash fury on this engineer for his insinuation, but then he thinks, you know, it is a little unseemly hot down here. So he asks the engineer what he would need to cool it down, and before you know it, six weeks later they have a working air conditioning system.
Months later, many improvements have been made. One day, God's feeling particularly cocky so he calls Satan down in hell and asks, "Hey there, buddy. Hot enough for you?" to which Satan truthfully answers, "Actually, it's a nice 73 fahrenheit down here. Perfect really... And we've almost got escalators installed, flush toilets... yeah, this engineer you sent down here is making the whole toil thing a lot easier."
God becomes furious.
God: "Well that won't do, you've got to send him back up right away!"
Satan: "Not a chance! This guy is great."
God: "I'll sue!"
Satan: "Hah! Where are you going to get a lawyer?"