That point is made in the article - he could have simply said the Grandfather died that week, and it would have been accepted. Instead he doubled down on going on attack, most likely because it did feel like a lie when he said it or was not the actual reason he missed the proceedings.
His grandfather did pass away a few days prior.
Depending upon what was happening with the related family, there can be a whole bunch of things that need urgently taking care of in relation to it.