The chain of descent that began in 2.62 reaches its end here. Anger produces delusion — the ability to see clearly is lost. Delusion erases memory — the person forgets what is right, forgets past lessons, forgets who they are. Without memory, the intellect collapses. And without intellect, the person is finished.
Consider termites in the root of a tree. They start small, invisible, quiet. By the time the trunk cracks, the damage is complete. The chain from dwelling-on-objects to total ruin works the same way — slow, hidden, and devastating by the time it surfaces.
Read together with 2.62, the full chain is: contemplation of objects, attachment, desire, anger, delusion, memory-loss, intellect-destruction, ruin. Eight links. The warning is stark: guard the mind at the very first step, because once the chain starts, each link pulls the next almost automatically.