Petitioner and the Notary looks like the same handwriting and just one person, especially the looped J. If it was signed by someone in Cuba this person may have signed as both people, maybe there wasn’t a U.S. Citizen who was a notary readily available.
The two signatures both say petitioner to the right so they should be identical. The US State department witness in Havana used a rubber stamp and seal.
Bigger issues may be why has that candidate with $6.9 million in unpaid campaign loans, and possibly leftover campaign cash, retired to a non-extradition country, and why is WI treating such a fugitive as a serious petitioner, and did the state department’s involvement in that petition coerce or intimidate the Democrat, Haas into breaking WI law and NOT requiring any payment of estimated cost at the time of his petition?