Here's the reply from the US Embassy in Singapore...Your friend might want to
give it a try! ;)
Visa applicants are encouraged to file their applications in their home
countries if they have not been in Singapore for a significant amount of time.
The reason for this policy is that the visa officers at the U. S. Embassy or
Consulate in an applicant's home country are more familiar with his or her
circumstances and documents than the officers here would be.
However, anyone who is physically presen