Forum:Strange Occurrence During Main Quest

I'm playing on Xbox 360, and I'm at the part of the quest where Dr. Li is hacking the terminal to open the door in Taft Tunnels. I decided to stay in the room where the Enclave soldiers spawn to get fully repaired armor; I'm using Sticky from Little Lamplight as a pack mule. I wanted to get on the catwalks so I could loot the bodies up there for Tesla Armor, so I was jumping on the structure on the left side of the room if looking in from the entrance. It has a short railing around it and some pipes that stick out of the sides and turn at a 90 degree angle into the ground. I got on top by jumping on the railing on the far side, then onto one of the pipes sticking out. You only go about halfway up the pipe, but if you walk around it, you can climb on top. From there, I jumped onto white pipes that are along the wall and jumped off those onto the top of the structure. A running jump off the structure got me to where the Enclave were coming from.

I looted the bodies, then proceeded to take the hallway they came from. It ended with a ladder that I could open/close (like the one in the Chaste Acres Dairy Farm silo) and the constant sound of a Vertibird. The other way, there was a door to Taft Tunnels, which I took. It opened into a hallway leading to a balcony with two Enclave soldiers. There was nothing else of interest here, so I jumped down. It was simply an alternate entrance to the area. '''But upon going back to the door you're supposed to enter from, the Project Purity team, Dogmeat, and Seargent RL-3 appeared. '''I had both Dogmeat and RL-3 waiting in My Megaton House; when I went through the door to go collect Sticky, the game informed me that Dogmeat was waiting at Vault 101. Sticky was unharmed, and RL-3 was good for carrying all the armor Sticky couldn't hold.

'''I would like to know if anyone has had a similar experience, or if they know why this happened. Thank you.'''