Q. I bought a rather long list of items at a kosher store, and I was clearly cheated when being charged about ten dollars for something I did not buy. I didn't notice until I got home and I was debating if to go back and waste time that is more valuable to me than that sum. But I thought that just being mochel and forget and forgive the seller may not be correct, as he may be doing the same to other busy uncaring customers, and I may be indirectly sponsoring his stealing.
What is the correct thing to do in such situations? (I did go back, and the embarrassed seller returned the money).
A. As mentioned above in question 2347: Horav Shlomo Miller's Shlit'a opinion is that one must judge others Lekaf Zechus, giving them the benefit of the doubt. If a wrong was done, we must assume it was unintentional and against their conscious will.
It is quite possible and common that the cashier made a mistake, when many items were being checked out or there are many customers waiting in line.
The fact that the seller was embarrassed, does not prove that he consciously and willingly overcharged, since people also get embarrassed by mistakes they make.
On similar situations, even when a Din Torah is involved, people assume the worst on others and neglect to realize their own mistakes and that the reality is that they were the ones mistakenly cheating.
As mentioned, the above is of utmost importance in the current Yemei Ratzon times, when we prepare for the days when Hashem will judge us all, and we wish it will also be Lekaf Zechus.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a