Here's a real-life example from the other night which may help to muddy these waters further.
ACBL club game, bidding boxes in use, we had the following auction with South dealer:
South, my partner on this auction, is in his late 70's and is prone to 'senior moments'. In particular, he is somewhat awkward in the handling of bidding cards. For example, he frequently replaces them in the bidding box upside down or out of sequence; I normally have to 'straighten out' his bidding box at least once per session.
In the passout chair in the given auction, he bid 5NT.
This might be termed an "obvious" mechanical error. Clearly there is no bridge hand which would bid only 2
♠ and pass over 4
♠ that could bid 5NT here. Once apprised of the mistake by the opponents, he made a 25A correction to 5
♠, I made 5 and nobody gave the incident with the bid cards any further thought (until I made this post, obviously).
Some in this thread have advocated for an "all bids stand as made" approach, disallowing ANY change of an unintended call, even one as obviously inadvertent as the example given above.
I think this is too extreme a position. Certainly, if I were EW, I would not want to "earn" a top board by forcing my opponents to play 5NT on this auction. On the other hand, allowing a change on this auction forces TDs (who are not generally present at the table during the original auction) to make judgments about "was this call unintended?" and "was there a pause for thought?". Clearly some lines must be drawn somewhere, but I don't see how TDs can be expected to rule consistently given the current wording of L25.
Does it make sense to separate the "unintended" and "pause for thought" components of the law? So you might, for example, permit any change of an "obviously" unintended call regardless of any pause for thought. (This would require a perhaps-impossible-to-formulate objective definition of "obviously"). Or you might alternately allow any immediate change and not require any standard of intention.
One thing I do think is clear is that the Laws should incorporate strict and (very probably) different guidelines for bidding boxes vs spoken vs written bidding and/or screens vs not.