Are there risks involved with lidocaine solution being injected into a person and then not removed?

Whomever was aghast was also ignorant of the pharmacodynamics of lidocaine. Lidocaine is fat soluble. That means it attaches to fat cells and nerve sheaths immediately, then gets absorbed slowly by your blood stream where it travels through your liver and eventually gets excreted. The process takes 24 hours from injection to excretion for the small amount of lidocaine that you described. It can't be removed by any mechanical process. Even lipo can't remove more than a small fraction of injected lidocaine. Pain during the injection process is either from injecting under higher than average pressure or from insufficient buffering of the pH of the lidocaine solution.

The tumescent fluid used to locally numb the area for Smart Lipo is a diluted amount of lidocaine. The amount that can be safely used is calculated by your weight. This amount is safe whether it is aspirated back out or not. It sounds like very little was infused and should not have been an issue as the surgeon was implying. This sounds like a classic case of a doctor putting down a colleague to make himself look smarter. And needlessly stressing you out in the process.

The only way to remove the lidocaine in the tumescent anesthesia is to perform the liposuction procedure itself. The vast majority (95%) of the tumescent anesthesia is salt water.  So if liposuction was not performed, your body will absorb the fluid and you will harmlessy urinate it out.