Well, today I learned that two things can break Captain America's shield.
1.) The Infinity Gauntlet
2.) UPS shipping
As an added bonus, the Infinity Gauntlet doesn't work either. Maybe Cap managed to throw his shield at it to knock it out before it was shattered to pieces. Although I suspect it has more to do with the broken rattling noise coming from inside the base.
Time to call SS returns and get in line for a replacement.
On the bright side, I may get to destroy a statue firsthand if Sideshow wants to see it destroyed before sending out a replacement.