Well, that's awesome!
It could have been any number of things, most likely an app or even Windows updating in the background. Once the update was done, the resource was released.
I had an app, Nir Sofers Wireless Network Watcher, that would poll my network at 5-minute intervals. For months I could not figure out the "stutter" in my audio and video. I happened to notice it polling one day and also noticed the stutter. I changed it to 30 minutes and it was more tolerable.
Keep us updated and come back if it presents again.