I for one thunk problems rooted way before that in 2000 as Vito tried to push and consolidate his power becoming a sort of boss of all bosses by taking over Ontario.
It didn't take much for the siderno group to set him straight by killing pane pinto, his main man in Toronto. That push into Ontario might have given the siderno boys Extra reasons to find unhappy campers in Montreal and unite to push the Rizzuto family out. The bigger you are, the larger the target on your back is
One of the two Ndrangheta members that was killed in Toronto by Panepinto is named Antonio Oppedisano. Domenico Oppedisano was appointed capo crimine in 2009, I always wondered if they were related. If they were it may share more light in the strained relationship between Montreal & Toronto.
^^^^ Antonio Oppedisano was not related to Domenico of Rosarno.
Vito Rizzuto and his father had allies in Ontario going back to the 1960s. Panepinto, who was unlikely even made, was not the most important ally of the Montreal Mafia in the year 2000. Nino Cammalleri (the uncle of Vito's wife, Giovanna), Peter Scarcella, Giacinto Arcuri, Frank Campoli (the husband of Giovanna's first cousin), Nicola Genua, and the Caruana-Cun treras were the far more important Sicilian associates in the GTA.
Despite what many mobwatchers think, the Commisso brothers in Toronto facilitated the expansion of the Montreal Mafia in Ontario in the late 1990s (see The Sixth Family book; doesn't matter which edition). A member of Nino Cammalleri's family married into the Commisso brothers' family in 2005/2006.
In 2001, we know that Vito chaired a meeting in the GTA in which he announced that he wanted to amalgamate Italian mafia groups in Ontario and Quebec. To think he could amalgamate all such groups would be absurd, but all of them at the meeting got on board. Members of the GTA Siderno Group were present at the meeting. We found out only last year that individuals from New York's Gambino Family were also at the meeting.
After Vito was jailed in 2004, the GTA Siderno Group's Carmelo Bruzzese continued to have contact with Francesco Arcadi for more than a year (may have been up to 16 months--I'll check my computer in the morning), as Bruzzese was instrumental in helping the Montreal Mafia in the corruption of public-works contracts in Italy.
Back in 2008, mostly Italian-language articles were published about the Operazione Orso Bruno investigation in Italy that targeted the Montreal Mafia leadership. Bruzzese, because of his close association with Vito Rizzuto, was charged with being a member of Cosa Nostra. On another forum, now essentially defunct, where board poster Hollander and I were members, he posted the odd English-language article about the investigation and Bruzzese's being arrested and charged. Back then, Hollander and I didn't know who Bruzzese was. Nor did we know of the criminal collaboration between the GTA Siderno Group, the Montreal Mafia, the GTA Sicilian drug traffickers like Genua and son Ignazio, and the Commisso clan in Calabria--all of this was revealed after the July 2010 culmination of the antindrangheta operation in Calabria, as the four-volume arrest warrants published two months later mentioned all the names and all the ties.
Past criminal ties--and even present criminal ties or family ties--do not guarantee future collaboration. The Commisso brothers forged very close ties with Nick Rizzuto Sr. in the 1970s; the brothers felt no loyalty to Giacomo Luppino and the Violis then and later in the 1980s, 1990s, and 2000s, just as they felt no loyalty to Domenico Racco, whose 1983 murder by the Musitanos could easily have been prevented by the Commissos' intervention. Scarcella and Rocco Remo Commisso had been close ever since the Commissos decided not to kill Scarcella in the early 1980s. The Charbonneau Commission revealed that Domenico Arcuri Jr. had very tight ties to the Cammalleri clan in the GTA, but did that stop the Arcuri brothers from allying themselves with Montagna and Desjardins? The intermarriage between the Commissos and the Cammalleris likewise seems to have had no real effect on the decision of certain GTA Siderno Group members to exploit opportunities presented by the mob war in Montreal.
If we look again at all the events and incidents involving the Italian underworlds of Toronto and Montreal between 2000 and 2006--maybe even as late as 2008--the newer information and evidence makes you see that for every criminal venture that went well, some other venture went horribly wrong. Or there was a murder such as that of senior GTA Siderno Group figure Vincenzo Raco, whose killing may have been ordered by Arcadi.
There is even a possibility that the murders and attempted murders at the Moka cafe in Woodbridge in 2015 are a result of renewed tension between certain GTA Siderno Group members and the Montreal Mafia--just reread one of the articles published at the time that named one of the two previous owners of the cafe.