Anonymous participant 676 first off, a cancelation is different than a rejection. In the cancelation, some embassies supply the reason why in the notice, while others don’t.
Do you know why your application was rejected? Have a way to fix it for next application? If you are extending your Cambodian visa, would it be the same visa though, just an extension stamp?
So Embassy staff don’t work on the weekends, but it seems that their is a delay between the embassy staff approving the visa and you receiving the approval. This results in receiving the approval email on the weekend.
Also, did you merge the documents into one pdf? There have been a few applicants who mistakenly tried to upload separate documents, not realizing that every time you upload a new document, it deletes the previously updated one. So for each upload tab/option, you can only upload one pdf.
To apply from a different country, your friend would need to travel there first. That seems like a lot for a tourist visa. Maybe your friend needs to cancel this vacation and apply in a few months