Wilson Pakula is the authorization in New York State that allows a registered voter to run for the primary of a party they are not registered in already. Repeatedly referring to the shenanigans of State Senator Malcolm Smith, City Councilman Dan Halloran, Republican Party officials in the Bronx & Queens, and the two Spring Valley officials as "election rigging" is at best lazy reporting at worst intentionally misleading their audience for the purpose to sensationalize the news.
Money dealings of these public officials is where they went awry of the law, implicating elections being rigged trades trust in elections for the chance of increase in ratings or increase of sales. It is not a minor infraction of public watchdogs to the public in the deceptive perceptive that these politicians' corrupt self-enrichment could somehow corrupt the election results and thereby our democratic institutions. Primary ballot access has little to do with general election results, and certainly couldn't be categorized as 'rigging'.
Typically partisan primaries are limited to registered members of the party, New York State allows for fusion ballots that allows party members appear on multiple parties' primaries and on multiple ballot lines in the general. To do so you would need the party chairman of the respective municipality to authorize it, in the Smith-Halloran scandal Democrat Smith would need the Republican chairs of 3 out of 5 of the borough party chairs and those authorizations were what Republican Halloran was assisting Smith in attaining in his quixotic effort to become Mayor of New York on the Republican ballot line. These party chairmen's authorizations are called by the shibboleth Wilson Pakula after the legislation that allows the cross partisan ballot.
No actually vote tampering nor election rigging was threatened to occur, it was very similar to Bloomberg over paying Independence Party officials for political consultancy services. The difference is the money that Smith and Halloran was not their own and therefore illegal. The greatest source of corruption is the dependency of private contributions; had all elections were citizen funded as Laurence Lessig has proposed or publically funded as Wolf-Pac.com has proposed this scandal could never have occurred.