Is there grammatically expressed evidentiality in Russian?

In this paper it is demonstrated that evidentiality can be expressed in Russian by grammatical means, namely, with the help of a grammatical construction called “Genitive of Negation”. It should be specified that the opposition is only possible in a limited context of several stative and momentary verbs of location and appearance that allow “Genitive of Negation” for a referential or quantified subject. In this context Nominative expresses simple absence, while Genitive expresses OBSERVED ABSENCE, i.e. the presence of the OBSERVER as a participant of the situation. From the typological point of view it is interesting that in Russian the observer is a FLEXIBLE (= MILD, = SECONDARY) egocentrical: the role of the observer can be fulfilled, in different registers of interpretation, not only by the SPEAKER but also by other subjects. The question is, whether in languages with grammatical evidentiality it is always the case that the role of the subject of evidentiality can only be fulfilled by the speaker, so that the subject of evidentiality is a RIGID (= HARD, = PRIMARY) egocentrical?