Invincible season

[Damien Hall]

Not an *American* usage (that I know of, anyway), but I would be interested to
hear anything that people on this list have to say about this:

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'Patrick Vieira made it an invincible season with a 66th minute winner.'

from a BBC Sports article about Arsenal FC, the English Premiership (football)
champions, not losing a match all season.

http://news.bbc.co.uk/sport1/hi/sports_talk/caption_comp/3721165.stm

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If it's the season that is being described as 'invincible', not the football
club, which is certainly the way this sentence reads on first reading, this
seems like a 'middle' use of the adjective to me.  I seem to remember
occasionally coming across 'middle' uses of adjectives like this, where active
meanings are substituted for usual passive ones, but I haven't got any more
examples to hand.

With *invincible*, at least, this usage is otherwise unattested in the first
hundred of each of a Google and a Google Groups search, and neither *OED* nor
*MW* lists anything other than a passive meaning.

The more I look at this example, the less I am sure what I think is wrong with
it, but I do think there's something.  What do other people think?

Damien Hall
University of Pennsylvania