BNet disconnect causing placement loss

During my most recent placement match, I disconnected from BNet and was unable to reconnect through the launcher despite having shut down the game and relaunching it completely. There was also another player on the opposing team who was disconnected as well, so I know that it was server-side and not user-side.

If the source is server-end, why did I still get penalized with a loss?

This sounds more like coincidence, as there have been no major server issues for a while now. Also, it’s entirely possible you and that other player have a hop between you both and Blizzard servers, which caused a disconnect. As for SR loss, that is covered here in the stickies: Overwatch Technical Issues, SR Loss, and Leaver Penalties