A more thorough explanation:

Definition: Obiter ex post facto refers to a court's decision that was expressed in unnecessarily broad terms, according to a later court. Some experts argue that this is not a type of obiter dictum at all.

For example, a court may make a ruling in a case that goes beyond what is necessary to decide the case at hand. If a later court finds that the ruling was too broad and not necessary to the outcome of the case, it may consider it obiter ex post facto.

Another example could be a judge's comments during a trial that are not directly related to the case but are still recorded in the court transcript. If a later court finds that these comments were not necessary to the decision in the case, they may be considered obiter ex post facto.

These examples illustrate how obiter ex post facto can occur when a court goes beyond what is necessary to decide a case and makes statements that are not directly related to the outcome. These statements may be considered unnecessary and too broad by a later court.