I’ve already created topic in general discussion with the same title to figure out what was that. The most people agree that wasn’t ping or server lag. Brigitte’s shield was up and Widow still caused damage. I recorded a video of what happened from my point of view and Widowmaker’s point of view with the different speeds.
Brig’s shield doesn’t come out immediately. The .25x can be deceptive for the animation, she did shoot while you were healing. This particular case seems to be an artifact of latency and favor the shooter, not the bug you’re talking about.
What is your ping normally, it could be desync with the server, the widow could be playing with high ping.
You should set up a custom game and have a friend, or use that new workshop mode that let’s you control the bots abilities https://youtu.be/Jjrq6AhtyDc
Fast forward about 5 minutes and that’s where he shows the workshop code and shows what I’m talking about, could do that with a brig bot, and try seeing if you can replicate it happening.