Expression for losing something that you never really had

Solution 1:

Your friend missed out on those points. This idiom is commonly used to indicate missed opportunity, though it doesn't suggest specifically how that opportunity was missed.

If you find his experience was unfair to his position, you could say he was shorted or short-changed those lamented points: he was given less than was fair, depriving him of the full reward of his work.

Solution 2:

Notional loss?

By not buying a lottery ticket, one could "lose" a million dollars.

As opposed to a real loss of a dollar or two by buying one.

This answer and the OP's example may not seem to match. That is because in the example, the loss is real, and so the example doesn't quite serve the purpose of the question.

( meta: For some reason, I'm unable to post comments for now.
A nominal loss is a symbolic loss or usually, an insubstantial, so negligible, loss – but real loss. It's not hypothetical like notional loss. )