Hi Pinal,
I was facing similar problem and resolved it.
First check whether the scope variable for video src has value when the tag is getting created. For this you can use ng-init in the video tag.
If you see that the scope variable does not have the proper value just do the following.
1. In HTML put a ng-if in the video tag (like ng-if="asdf")
2. In controller one you set the value for scope variable for the video src, make asdf=true.
Hopefully this will work. In my case it worked actually.