When she starts dredging Matt Shea's past, her past becomes fair game.
I assume you read her talk about his divorce in the article. There's also this:
From the Spokesman Review
Democrat Amy Biviano’s campaign for state representative in Spokane Valley mailed this flier this week. It features a road rage incident involving her opponent, Republican state Rep. Matt Shea. Police reports indicate that although Shea pulled a gun from his glove compartment during the dispute, he did not point the gun at the other motorist, as Biviano strongly suggests in her mailer.