I think such things are not necessarily related to yoga, but to life in general. Of course you could find a scientific reason. If it broke in a million pieces (mostly little square ones) it was probably tempered glass, made to be safer when it breaks. If a little part of it was hot and a cold water drop hit it, it could cause it to break.
Splash a little cold water on a hot light bulb and they shatter.
But i digress. The scientific reasons are beside the point. like Katrine says, if instead you look at what’s going on in your mind when synchronicities happen, you get more relevent information for yourself.
It’s not that something you did made the glass break; it’s where you were in your consciousness when the glass broke
that is important. These things serve to remind us that we are connected to what happens around us, even though “scientifically” we seem to not be. But don’t obsess with it as that takes you out of the moment. Just watch.
No contradiction here. You get more relevant information about yourself by looking at what’s in your mind when the glass breaks; and someone else get more relevant information about the world and the interrelations about things and events by looking and examining at the possible causes systematically and analytically.
You don’t get much info about yourself by analyzing; and similarly you won’t learn much(if any) about this physical world by looking inside.
Hope one day, the people from the two streams will understand the differences both in objectives and methods, and will start to understand more about themselves and the outside world. 
Hi all
Alvin wrote:
Actually; I am not discussing what is going on in the mind when the glass breaks. I am suggesting that being thrown into the now like Lili experienced, might bring you in touch with Silence/Consciousness/Emptiness - the source of mind. You are no-thing/no-body in that instant - any mental activity has been stilled for a split second. That glimpse; that gap; can be recognized. Not by the mind (it contains the mind) - but by itself. And you are that.
I agree, Alvin. When mind sets out to understand, different methods and objevtives are needed. However - the source of the mind is the source of the world also. One source seeing itself everywhere. It is understanding itself.
I see you what, Katrine. Here’s a way to systematically create that silence then: intentionally switch the glasses of your family members/close friends with a unannealed glass. Then it is a systematic way of inducing that kind of stillness in them, though with no guarantee that they will appreciate
Well…
Alvin:
Silence need not (and cannot) be created by you or me. Silence already is. You and I (our personalities) do not have the power to induce stillness in anyone. In fact - that very intention casts you straight out of silence - it is effort/doing. Only silence can resonate with silence. In other words: when i am silent and you are silent (and I mean totally silent, whether we hear,think, feel or see anything or not) - we are totally synchronised with Being. One silence. Only the spontanious action of being can bring you in touch with itself.