Yet still it might have been a pretty simple wound compared to Ichigo's, who suffered all kinds of cuts, the demon magic lightning bolt and also Byakuya's Bankai in various forms. And Jidanbou has now had many days of rest on his own, as well.

But it could be a plot hole, as well. It certainly looks like one. I was just trying to come up with any reasons why it necessarily doesn't need to be one.