I think a better fashion is to have copies of the code in use sent to
a third party or tournament organizer beforehand,
Not many commercial Go programmers will give their code to a third party.
BTW people have (alledgedly) DIED over Go code plagiarism, and we're not
even talking sourcecode here.
The current official world champion, KCC Igo, alledgedly contained code from
Handtalk.
Protests were made to people in NK.
Soon afterward, the manager of the KCC Igo team got executed.
Rumor was that it was over the embarassment caused by the plagiarism, but
the reason stated was financial fraud.