Cabela’s in Indiana not selling standard capacity mags to IL residents

There were rumors going around that some Indiana gun stores were not selling standard capacity magazines to Illinois residents. The rumors are true. Today, a Mom-at-Arms reader/supporter from the Chicago area went to Cabela's in Indiana and attempted to buy an AR magazine. He was asked to show ID just to buy a mag to prove he's not an IL resident. Here's the video evidence of this happening that he provided. Is this a Cabela's/Bass Pro corporate policy?