Lt. Kerry was more than likely the type of corner-cutting finagler that wasn't uncommon to the armed forces, both officer and enlisted, during the days of mandatory military service.
First, we know that he engineers a transfer to what he thinks is going to be just a routine small-boat coastal patrol operation. You can imagine his chagrin when he found out their mission had been changed to an aggressive reconnaissance in force stance shortly after he made the move. Not quite the assignement he'd been looking forward to.
Secondly, we know that he was a bit of a "stockade lawyer," who carried around a copy of the rules of engagement in his hip pocket and, according to his own statements, wasn't adverse to waiving them around under his senior officers' faces on occasion. Kerry knew the rules, chapter and verse ... no doubt about it. So he probably knew about the "three wounds" ticket home thing too.
Thirdly, Kerry was probably the one who wrote up the initial recommendations that he be awarded the medals he eventually earned and submitted those documents himself as part of his after action paperwork.
Fourth, Kerry has stipulated that at least two of his wounds were "superficial," requiring no hospitalization time and that a third wound only cost him two days of "off duty" time.
Fifth, Kerry has refused to waive his Privacy Act rights and authorize the release of the medical records that were part of his military service. If he's so proud that he earned those records, he certainly shouldn't mind the public disclosure. After all, that disclosure can only bolster his status and the war hero image he's trying to project, right?