There is no evidence of Mossad involvement. Far from me to defend Israel's spy agency but the article only mentions a possible connection to Azerbaijan.
The Russians claim otherwise - https://www.rt.com/news/646794-german-spy-chief-arrested/ -... According to them, his private agency also sub-contracted some high-profile kidnapping to Yaakov Perry, the former chief of Israel’s domestic intelligence agency, Shin Bet.
This one doesn't since it's a US outlet and they don't have free speech in the US, on Israel-related matters. The Irish Times reported the Israel connection though.