I also use this method to apply butter to a hot pan when making grilled cheese! Just melt a little patch and place the bread, cheese, then bread. When is time to flip, hold the sandwich on the spatula while applying butter to the pan for the other side.

No hate to those that prefer mayo, but I love that buttery crunchiness.

The lower leg moving would be an obvious sign, but they may be watching above the knee (where the muscle is actually contracting to create that movement) for even a twitch. Even absent that, without other symptom complaints they may just not be holding much weight with that one test. If you came in complaining you recently started dropping things, tripping, or injured yourself in a fall, that would carry more weight.