Evidence of synchronicity? I am not really sure there ever can be such a thing. Synchronicity seems to be such a personal phenomenon it would be hard to really prove that a thing was not coincidence. One event happening in connection to one person with significance, to another, can be passed off as coincidence. I'm not really sure anybody really needs to prove synchronicity. Most often synchronistic moments are only intended for the person that receives them.
     I do have a few incidences of synchronicities of my own. One time, while I driving, I remember thinking that I needed to call my friend that I hadn't talking to in a while. It was almost as if his image popped into my head. I called him within a minute and ,when he answered, he told me that it he had just settled into a meditation and had begun focusing on me while in meditation. Also, I used to watch a T.V. show that would have an episode with the perfect message for me to hear when I was feeling down. This happened almost ten times.
     Not that I could ever give proof that there were interconnected occurrences or anything. I do not really need to. But, I do have experiences of them and that is proof enough for me.

     We are all connected to the ebb and flow of energy around us through our sub conscious. This connects us to our surroundings, group consciousness and other knowledge. It is through this that allows synchronicity to work around us.