Man cuts off penis in restaurant. Why?

This bizarre story as reported by BBC:

A man cut off his penis with a knife in a packed London restaurant.

Police were forced to use CS gas to restrain the man when they entered the Zizzi restaurant in The Strand on Sunday evening.

A Metropolitan Police spokeswoman said the man was aged between 30 and 40 and that his injuries were self-inflicted.

The man was then taken to hospital in south London where his condition is stable. It is understood surgeons were unable to reattach his penis.

There is more in the article, but the main question: why would a person cause himself that ultimate in self-destruction, remained unanswered.

I have checked the restaurant where the deed was done:

Zizzi is a chain of traditional Italian pizza and pasta restaurants that cook all their pizzas in wood burning ovens.

Nothing extraordinary - just another pizzeria, and one should not expect anything special in the manner of food items served. It is definitely not a Maxim or a Peridot or whatever. And in any case, if the gentleman meant something in the line of criticism, why had he cut off his own member and not that of the offending chef?

Mystery... The only hint could be derived from that last sentence in the quote above:

It is understood surgeons were unable to reattach his penis.

Probably chopped it too fine. Was Zizzi out of pepperoni by any chance?

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