AudiWorld Forums - Mechanic at dealership forgot to clamp fuel hose

My 2015 Audi Q7 TDI (with 55k miles) broke down with a "bad diesel pump". Went to dealership for repairs (under warranty) where they replaced a long list of parts including; fuel filter, pump, pipes, fuel lines, clips, adapters, fuel distr, washers, plate, hose clamp, bolt, gaskets, seal ring, hoses, module, flanges, couplepiece, and pump. Driving the car home (about 20 freeway miles) from the shop it smelled more and more strongly of diesel fumes. I opened the hood on the driveway, and noticed a clamp hanging un-clamped on a hose near the fuel filter. Fuel was dripping out and had gotten all over the engine bay and was dripping through the engine bay to the ground forming a large car-width puddle on the driveway. Because, the car could not be driven or towed with a fuel leak, the dealership sent a mechanic to my house who closed the clamp and drove the car back to the dealership to be cleaned. The dealership assures me that they will wipe down and steam clean the engine, but I want to know how bad this screw up actually is. I don't have a lot of confidence in their quality control if they missed something this obvious. Assuming they test-drove the car after working on it, a mechanic should have noticed these fumes and leaking fuel.

I am concerned that steam cleaning will not be able to reach all the cracks and crevices the fuel may have seeped into.
I'm concerned that steam cleaning the engine could damage the engine in other ways (electronics, condensation etc)
How corrosive will this be in the long term?
Has this caused any irreparable damage?
Does this affect resale value?
What should I be aware of before I accept the car back as "fixed"?