Playing beyond third out

[MD Longhorn]

I don't see these as equivalent at all. For many reasons. Really, not even similar. The first involved inadvertently continuing to play after a legitimate 3rd out. The one you posted, well, doesn't. At all.

In your sitch, the appeal never happened, and the umpires should never have gone back. Head Coach needed to appeal this while umpires were still on the field. I'm not sure I follow why B2 was called out anyway - probably a misunderstanding of what you wrote on my part though. But even if B2 should have been out, there are rules for appealing this - and those rules were not followed. (Not to mention that AC doesn't have the authority to do this anyway - assuming HC is still in the game).