giving 120% ??

so, recently I met with a man who was looking for a job.  Among other things he mentioned he would give not 100%, nor the popular 110% but he said he would give 120% to the job.

Since I was taking notes about my impressions of him, I wrote down in the margin, "120%".

After he left, I reviewed what I had written, and began adding up the negatives and positives.  Then I came across the said percentage.  I didn't really know whether I should count that as a positive or a negative.

I mean on the one hand, the 110% has come across as a buzz word and been generally accepted as meaning,"someone who gives more than others".  But what if now someone is proposing to give 10% more than that, even?  

On the other hand, is it even possible to give more than 100%?  Which would be giving more than your full amount, I think.  Now I'm no mathematician, but I don't think it's possible.

Is that someone I should recommend for the job?  Do I really want or need someone who gives more than that?

I mulled this over and, realizing there were more candidates to talk to, decided to wait and see.

However there is a greedy part of me that wants to hold out for someone who gives 125% or even 130%.  Maybe we should hold auctions instead of interviews.