In the documentary 'Installation Art: Who Cares?' Tino Seghal claims that his insistence on oral contracts without any physical documentation counter-intuitively ensures the work is transferred without error. He argues that by doing it this way, the parties involved are more invested and therefore more likely to stay true to the original work. That if things have to be interpreted from written instructions, the risk of someone treating them heedlessly is much higher.
Which is a valid position. Difficult to test perhaps, but certainly intuitively plausible.
Unfortunately, he completely discredits his own reasoning one sentence later by wishing to supply an additional example. He says that one can easily see this idea at work when you learn a language. He claims you didn't read the dictionary and a book on grammar to learn a language, you learned it from your mother and she didn't have any written instructions on how to teach you either. He then says that nobody fears any particular language is going to disappear and most things in life are passed on from person to person.
Which is where I have to stop him. One of the first things any linguist will tell you is that all language is constantly changing in subtle ways and there are many languages dying out all the time because attention has shifted in other directions for myriad reasons.
A dictionary is also not a learning tool. The dictionary is there precisely to document the meaning and usage of words as closely as possible, because otherwise there could be no consensus on the use of language. Without a clear reference point, language will over time be defined by the lowest common denominator of knowledge, which will invariably lead to language being ever-increasingly impoverished because nobody knows all the words in a language and most people barely know any.
This ensures that Tino Seghal's work wont survive after his passing. It might exist for a while but it will perpetually deteriorate. What he has found in this oral contract is not an assurance of veracity, but a way to strictly control the distribution of an economic good that essentially consists of nothing more than the right to do something with your own body.
Which is a very crafty way of dealing with a particular economic situation, but if Tino's concerns genuinely lay with preservation rather than financial gain and political reputation, something like a highly detailed instructional video seems like a much more plausible solution to the problems inherent in his field of work.