7/18/16 Update: The witness has now elaborated on Reddit to say they did not see the UFO in person, but only after viewing the video later. This means this could be something on the camera lens like a bug. However, there is no clear evidence that this is the case right now.
A really intriguing video showing a black object moving in and out of a large contrail or cloud of smoke in Vancouver was posted on YouTube by the witness:
I saw a strange looking cloud outside my home in downtown Vancouver BC, and I took some pictures of it and decided to get a video too. What you see in this video was not what I saw taking it. The object was discovered today, while going through my pictures on my phone. I don't know what I'm looking at. I don't think it's an insect on my window as it seems to "materialize" and then vanish within seconds. The object's maneuverability and speed is incredible. I'm upset I didn't keep recording, as you can see at the end of the video, the object is clearly visible. But I had recorded a cloud for a minute and thought I got enough out of this cloud phenomenon.
What do you think this UFO was?