Member's Doppelgänger?

First off, for those who aren't too familiar with what a doppelganger is, it's supposed to be a demonic entity that takes shape of a specific person. If said person sees itself in the "doppelganger" (demonic) form, you will die that day/night. With all this being said, this experience was a very interesting beginning to a very interesting investigation ahead. Lets get started.

Let me set the scene before leaping into what happened...This took place several years ago at a location that I'd like to not name at this time. We were the first team allowed to do an investigation in years. At the time of this experience, all but one member was at the location. Now, for the layout of the location...

There were two sets of wide double glass doors on the first floor. Once you enter the building, you can see two big staircases that lead up to the second floor and also has a big balcony. If you're standing on the balcony, looking down to the first floor, you can see the two sets of wide double glass entry doors. Now that that's taken care of, let us move to what happened that night. 

Out of all of our members that were at the location at the time of this incident, all but one of us experienced this. This was due to the one member finishing camera set up throughout the building. Myself, our team members, and our host for the evening were standing at the top of the balcony waiting for our last member to arrive, which would be at any moment. All of a sudden, we see the member walk to the doors and attempt to open them, but they're locked. I mentioned to our host that's who we were waiting for. In the 20-30 seconds it took our host to walk down the stairs and get to the doors our member had vanished. Our host even walked outside of the building, walked around the building, but he had simply vanished into thin air. We all gave each other the infamous "weirded out" look. Finally, I asked another member if she could call him and ask him to come back to the front and our host would let him in. So, she made the call.

She asked him to come back to the front of the building, asked what he was doing, and where he went. He confusingly told her that he was still on his way, and would be there in about 10 minutes. She grew silent and turned white as a ghost (no pun intended). Once she ended the call we all asked her what happened. She told us and we all had the same expression, and all swore to our host that was him. He didn't seem one bit surprised by this as similar things had happened before.

Sure enough, several minutes passed when our final member arrived, wearing the exact same thing as the assumed "doppelganger" had been wearing. We explained the experience to that team member which shook him up a little bit.

So, was this a doppelganger? Or just a coincidence? I guess we'll never know. But I do know two things for sure: I never want to hear about someone seeing my doppelganger twin, and, obviously, I never want to come face to face with my doppelganger twin.