Just Cut Down on the Salt!
This one is less damaging in the outcome but is side-splittingly hilarious the more you think about it. The doctor examining the leg and likely noticing the odd texture and squishiness of what they assume is a real leg.
Admittedly, real-looking prosthetic legs do look a bit swollen and bloated, but he should know better. “Retaining water.” Oh dear. This doctor is incredibly oblivious, or they have really improved the quality of prosthetics to the point you can’t tell them apart from real limbs.