As hypothesized, introducing noisy labels significantly increased aleatoric uncertainty, with an almost negligible rise in epistemic uncertainty. Specifically, mean aleatoric uncertainty for halogen atoms jumped from 0.06 ± 0.08 to 0.9 ± 0.1, while epistemic uncertainty increased from 0.01 ± 0.01 to 0.03 ± 0.02. In the halogen-agnostic scenario, the absence of relevant training data led to a more pronounced rise in epistemic uncertainty, with less substantial increases in aleatoric uncertainty compared to the noisy-halogens case. Here, mean aleatoric uncertainty rose from 0.06 ± 0.08 to 0.8 ± 0.2, while mean epistemic uncertainty increased from 0.01 ± 0.01 to 0.13 ± 0.05. Both uncertainty types remained stable for other atom types, indicating that these changes were specific to halogen atoms.