I'll stick up for Machado a little bit. Pretty much every 3B throws to first instead of trying to tag the runner coming at him there. There were two out and it's the surer play (If Machado notices earlier and stops, Donaldson could end up getting no outs).
So he tries to avoid the tag, and then gets knocked off-balance by the tag which he felt was hard, and he stumbled awkwardly. Of course, this is the guy who missed a season with an ACL tear, so he's probably not feeling great about being knocked off-balance awkwardly.
From that point they jaw at each other and of course neither is going to back down quickly because they want to show they're tough. Who knows what was said.
So today, he definitely shouldn't have thrown his bat and I would agree with a suspension. But, on the pitch that happened, he was being thrown at, near his knees, which, I surmised earlier, he may be kind of sensitive about. So, I don't think that's particularly cool either. It probably could have just been over if the A's had let it go and let the Orioles leave town, but because it was a 10-run lead and teams always have to make things "even" they endangered a star and in turn, had their 3B endangered.
Also, Donaldson was taken out that inning, so he actually threw his bat towards Callaspo, contrary to what people keep repeating. He wouldn't have any specific beef with him, would he? (Not saying it didn't look purposeful).
I think most of this garbage (like the Workman / Price junk) would stop if teams just didn't retaliate (Or if umps tossed guys more quickly instead of issuing warnings). OK, you feel like you're one down but who cares. It's not exciting, often starts from some perceived slight that isn't even a real problem and is just a bunch of players being overly macho.