[blml] "Demonstrably" - practical meaning?

[Guthrie]

[Nige1]
Such assessments are unlikely to be unanimous. Hence to be practical, 
such protocols depend on probabilistic criteria. They're certainly not 
"provable". But are they what Bridge law means by "demonstrable"?

[Grattan Endicott]
+=+ It would be wise to read the law once more. There seems
to be an assumption in many of the comments in this thread that
the law requires the Director to determine whether (when there
is a logical alternative) the action the player took was suggested,
demonstrably, by the UI conveyed from partner.  This is not so.
        The judgement the law requires the Director to make is
whether, when there is a logical alternative action, the action
taken by the player "could demonstrably have been suggested"
over that alternative. It is a case of 'could it have been', not 'was
it', and it is whether it could have been that the Director must
judge to be a demonstrable possibility. 'Demonstrable' eliminates
the obscure and requires the Director to stay in the real world of
what could be so. He does not have to judge that it actually is so.
       If the Director forms the opinion that an infraction of law (i.e.
that the player has selected an action that could have been
demonstrably suggested as above) and that the offender has
thereby gained an advantageous result, the Director is required
to award an adjusted score in accordance with Law 12C.
[Grattan Endicott]

{Nige2]
Thank you Grattan. I've reread the law (below) but I I'm still unclear 
what is the practical meaning of "could demonstrably". For example

  - In an old thread, when I tried to introduce probabilistic arguments 
as to what was suggested by unauthorised information, Alain Gottcheiner 
and many other BLMLers demurrred because, for them, "could demonstrably" 
seemed to mean "you would be able to prove it if necessary". And Grattan 
seemed to agree. I confess that I was amazed :(

  -  In a more recent case, Paul Lamford echoed that interpretation when 
he said that the agreement over what was suggested would have to be 
almost unanimous. Nobody (except me) queried this interpretation. :(

Do BLMLers really believe that "could demonstrably" means "provable 
beyond reasonable doubt". Surely, in the context of Bridge Law, it 
should mean "on the balance of probability". Or perhaps something in 
between. Grattan now seems to be admitting to a more practical 
interpretation. :) :) :)

But I still think the wording of the law could be improved to reduce 
confusion and to be of some practical help.

Perhaps: If a majority of the player's peers would judge it to be 
logically suggested - ideally this being the result of an actual poll -- 
or failing that -- the considered opinion of the director(s) or committee"

IMO, it would be even better if the poll, as to what was suggested, took 
place without those consulted knowing the actual result. IMO this, too, 
should be recommended in the law book.

[TNLB L16B1]
After a player makes available to his partner extraneous information 
that may suggest a call or play, as for example by a remark, a question, 
a reply to a question, an unexpected* alert or failure to alert, or by 
unmistakable hesitation, unwonted speed, special emphasis, tone, 
gesture, movement, or mannerism, the partner may not choose from among 
logical alternatives one that could demonstrably have been suggested 
over another by the extraneous information.