What is the test for a motion to declare a mistrial based on a witness's statement?

"A court should grant a mistrial motion based on a witness's statement if it judges the defendant has been prejudiced in a way that an admonition or instruction cannot cure. Because this is inherently a speculative matter, the trial court has considerable discretion in ruling on a mistrial motion. [Citation.]" (People v. Rices (2017) 4 Cal.5th 49, 92.) The trial court's refusal to declare a mistrial is thus reviewed under the abuse of discretion standard. (Ibid.)