last year a 1943 (copper or bronze) USA penny sold for $100,000 and so did a 1944 (steel) USA penny! in 1944 the STEEL pennies were shut off but a couple of them got through! just thought i'd let you know.
i dont think any one was trying to cause issues for you. a 1943 copper wheat penny is extremely rare, and i think that is all they were trying to find out, like someone else had mentioned all but a handful of the 43s were silver.