This isn’t due to “poor mechanics”, per se. This is the fatal flaw of a combination of 3 “elements mixed at improper levels”, with the volatility of tribalism making everything more chaotic and intense.
Element 1: The emphasis placed on umpires to “get the call right”.
Element 2: The imbalanced burden of “calling responsibility” placed on the PU at moment (or we could say – interval) of pitch.
Element 3: The lack of an Official Review System (of the play(s)).
What I’m sure happened is that U3 called Foul – however loudly/clearly or not – because he – from his vantage point – interpreted the batted ball to be off the foot.
The pieces add up – the ball is batted straight down and “kicks” forward. The batter doesn’t leave the box. And, F2 is… tentative(?) about fielding it (did he see/hear it off the B’s foot?). Obviously, the PU didn’t see/hear/perceive it to be off the foot, hence why he didn’t call it that way, instead, keeping the play live. There’s a lot going on here to “load” upon the umpires’ (plural) processors. This must be the end of the game, with less than 2 outs. This has likely been a tense game, as well, Pitch comes in, big swing with a metal bat (they’re loud ), and the ball trampolines off the ground. [Element 2]
Knowing this, about Element 2, some BUs factor in Element 1 more earnestly and eagerly than others, and try to be helpful. So, what they see / hear / process from 100+ ft away takes over, and they “call it”. Now, granted, if U3 had immediately “come up big”, and called / signaled foul by dashing down the line and “waving guys off”, he’d have likely sold it, and there wouldn’t be the “chaos and madness”.
However…
This is where Element 2 once again snaps its jaws and shreds these situations – Who has “primary authority / responsibility” on this? That whole “don’t step on your Plate guy’s d!€k” crude anecdote. There’s that pause, or reservation, or hesitancy – “I perceived <this>, I’m going to wait to see if my PU saw it too, he didn’t and nowOhNoTheMomentIsSlippingAwayFOUL!” (hands go up in Time mechanic). Now it’s too late, and we have bedlam. Let’s say that F3 had thrown to F2 in time, and tagged out R2, what then? Or that R2 remained at 3B only? We’d still have bedlam, but the offensive team would be pleading (3BC for sure, Batter, etc) that it hit his foot, and didn’t… didn’t U3 see it?! Surely U3 saw it!! He mechanic’d “Foul!”, didn’t he?!?!
Know what fixes this? Element 3, Video Review. I know it’s lacking on this particular game because of the ferocity with which the DHC approaches the PU. If Official Video Review was present, then there’d be gestures and genuflecting towards consulting the video; there isn’t. All the outrage is organic.
I understand, Video Review can’t afford to be everywhere, on each and every game. I’ve been in these exact situations, and I can honestly say, as all 4 roles – Plate Umpire, BU who “perceived something” and called it, CC who wasn’t directly involved, but had to mitigate and explain it all, and observer / supervisor watching it, either in the moment (like, in the stands or press box) or post-game.
I don’t rightly know how to “fix it” to “improve it”, short of implementing Element 3. Of course, I have my opinions on Element 2, but that’s for another post.