Well that could kinda be the point, in a way, he feels really happy with his partner (who communicates through the phone), so happy that all of his pains become insignificant and he "forgets about it" when reaching out for the phone. But as his blissfulness grows his pains also get increasingly smaller, not even being able to keep him from hurting himself to the point of getting killed without even caring about it... Or it could just be a guy doing a silly violent cartoon for his girlfriend, who knows? Glad you liked