Al Bumbry, 1994 Upper Deck All-Time Heroes #73

Here's an unusual card that's part of Upper Deck's 225-card All-Time Heroes set, released in 1994. It highlighted retired players, and not just the same couple of dozen Hall of Famers that we're used to seeing by now. For instance, the checklist features Al Bumbry, Lee May, Boog Powell, and Paul Blair. Though Bumbry is listed as an Oriole (he played 13 of his 14 big league seasons in Baltimore, save for a 68-game career-ending stint in San Diego), and the primary card photo depicts him in an O's uniform, the inset photo shows the outfielder wearing a Boston Red Sox cap. Presumably Upper Deck grabbed a picture of Al from his tenure as a Red Sox coach, which lasted from 1998 through 1993. I have the rest of the Orioles from this set, and all of them have inset photos with Oriole caps. What gives?