Incurring a penalty in the spiritual sense indicates that we have transgressed against a particular code of behaviour. We may not necessarily be aware of this code.
Psychological / emotional perspective: A penalty is in normal parlance a fine levied for a misdemeanour. It is a punishment imposed by others, often our peers, and will have this meaning in dreams. We will have upset someone without necessarily being prepared to take the consequences.
Material aspects: Dreaming of a penalty goal can mean, if we are shooting this goal, an opportunity to be in the limelight because of someone else’s mistake.
If the opportunity for such a goal is our fault, it is a warning to be more careful.