Several studies have previously reported ISC rates for TIPS-Pn that are inconsistent with experimental data. These rates correspond to time constants ranging from ns to µs, with some predicting observable quantities of triplets on timescales over which triplets have not been observed. These studies have often dismissed SF in dilute solutions and attributed triplet formation to ISC. For TIPS-Pn, we extend the work by Dvořák et al. to quantify diffusion-limited SF in dilute solutions, and show that SF can lead to observable quantities of triplet excitons for dilute solutions on ns time scales. We quantify an upper bound of the rate constant of ISC in TIPS-Pn and show that, conversely, discounting ISC can lead to an overestimate of SF.