Correctly using the term 'onsite' gives you an immediate 'pedant point' - congratulations !(Sadly UKB has a binary option only - as befits t'interweb I suppose, so you got a 'wad point' instead.)
Kuhn - go on don't keep me guessing: Alfred or Thomas?
Although Escher can be helpful in examining the 'Si O'Conner Fallacy' the usual point of reference in this case, 'The Scott O'Connor Postulate' [viz 'if some really big numbers are said to be pulled down in a plantation when there is no-one there to witness, can we believe the event occurred in fact?'] is perhaps more illuminating:
"…For as to what is said of the absolute existence of unthinking things first ascents without any relation to their being perceived, that is to me perfectly unintelligible. Their esse [to be] is percipi [to be perceived] " [ Berkeley, A Treatise Concerning the Principles of Bouldering Knowledge, 1710 ]
Subsequently re-articulated by Husserl as 'No witness no [wad-] point' in Logische Untersuchungen following his fabulous 1900/01 winter season in the Frankenjura, although regrettably the rigour of his methodology has been woefully abandoned by later devotees, notably Bocke, M....blah blah blah....