Did Plaintiff Diligently Pursue His Claim

16 Although it is undisputed that Christiansen subjectively believed his condition was asbestos-related, the key question here is whether he diligently pursued his claim based upon that belief. See Tolston v. National R.R. Passenger Corp., 102 F.3d 863, 865 (7th Cir. 1996) ("'[A] cause of action accrues for statute of limitations purposes when a reasonable person knows or in the exercise of reasonable diligence should have known of both the injury and its governing cause.'" (citation omitted)).

The parties agree regarding Christiansen's admissions, but use them to draw different inferences about Christiansen's diligence.

Christiansen claims that the undisputed facts evidence his diligent effort to seek medical confirmation of his suspicions, which was forestalled by contrary diagnoses until 2002, when his suspicions were finally confirmed.

Union Pacific, on the other hand, claims that the undisputed facts evidence that Christiansen had no doubt about the cause of his ailment from the time he contracted it, but waited to file his claim until January 2002, which he did before receiving a definitive diagnosis of asbestosis in November or December 2002.

Hence, according to Union Pacific, the correct diagnosis was ultimately unnecessary for Christiansen to diligently pursue his claim.