It seems exceptionally odd that someone you don't know is calling you out on this and not your direct manager. You need to talk to your manager asap and in the

It seems exceptionally odd that someone you don't know is calling you out on this and not your direct manager. You need to talk to your manager asap and in the interim a. Be extra careful not to "give away points" eg by missing stand-up due to timezone stuff and b. Document everything. It could simply be that you ran into someone looking for air cover for their own screw-up. It happens, sadly.