At the time, the media blamed the attack on the Tea Party--the first of many false accusations. The New York Times, among other mainstream outlets, wondered whether the pilot was "the first Tea Party terrorist."
It was just a few weeks later, in March 2010, that the IRS began targeting the Tea Party, according to the report of the Treasure Inspector General for Tax Administration. Members of Congress have struggled to determine the precise time when the IRS began its misconduct, with some speculating that it began after the Citizens United ruling in January 2010, which President Obama singled out in his State of the Union Address.
However, it is possible that the Austin plane crash might have played a role--a decisive one. Perhaps the IRS--or higher officials in the Obama administration--were not satisfied with the truth that the Tea Party had not been involved, and decided to pursue further information about, and harassment of, the anti-tax movement.
Update: John Sexton notes that Garance Franke-Ruta made a similar observation on May 15 at the Atlantic. John adds that the Inspector General's report notes that the start of the scandal began with an email on Feb. 25, 2010, while the New York Times post blaming the Tea Party was posted on February 23, 2010.