No one is certain what has happened yet. Some are claiming that it is as a result of caste, some have said that it is due to disrespect shown by this Ravidasi Sant, some in Vienna have said it was actually an internal family dispute.
FYI, many Sikhs will have Vidya Gurdevs from whom they learn the interpretation Sikh scriptures or shastar vidiya, so it is not an issue of having a living teacher. However, last living Sikh Guru passed the Gurgaddi on to the Sri Guru Granth Sahib and to claim that one is the next living Guru of all the Sikhs would be blasphemous and disrespectful if anyone claimed it.
There are rumours that this disrespected the Sri Guru Granth Sahib by sitting at the same level and by claiming that he was greater than the Guru Granth, but I doubt that any Sikh would kill him for saying such things without sitting down with him first and asking him to stop.
The Akal Takhat, the seat of Sikh temporal authority, has expressed its concerns over this issue.
Personally I feel that trouble is being fomented by political agencies in order to draw away attention from commemoration by Sikhs and others of the Indian army's destruction of Harimandir Sahib in 1984.
I hope the people in Punjab who are looting and destroying property to express tyheir outrage realise that they are just harming themselves and their fellow Punjabis.
D.