No argument with most of that, OzExpat.
I think a glance at the elevation view makes it clear that the procedure starts at the FV at 4000 ft, to be maintained until outbound in the racetrack. And the MSA is not relevant. The pilot was, without doubt, technically wrong to descend below 4000 ft, but I can see why he was confused.
But I do believe that the plan view is more confusing than it needs to be. Imagine a case where the procedure started at the FV at 2800 ft, but the minimum holding altitude was 4000 ft for separation from departure traffic. Would the plan be depicted significantly differently from what you see on the plate? It's not easy to work out which altitude applies where.