Impossible chime

I have an Italian friend whose house I visit every week so that we can talk Italian and read Italian novels. One week , for reasons I can't recall, he came to my house instead. We were in the sitting-room reading when he asked me if the ticking of the grandfather clock didn't get on my nerves. I replied that it didn't, but added that I had tied the chimes up many years before so that it no longer chimed. After about ten minutes, when the clock reached 1.30pm, it chimed. I was absolutely astonished, but being a good rationalist, I refused to interpret this as poltergeist activity and ploughed stoically on. The clock had never struck before and has never struck since! In fairness I should add that the clock needs to be wound up every 24 hours and I only set it going when I want to keep a special watch on the time or at weekends, Christmas etc. I don't know if this alters the odds for my coincidence. I must confess that I have never bothered to examine the "innards" of the clock to seek a rational explanation. I am putting it down to a example of the Uncertainty Principle on a macro scale!