One thought, particularly at VCU, is that the person who read the applicant's file and scored it high enough to get an interview may not share the consensus view of the adcom? I don't know.
I also don't particularly have a ton of faith in the extent of the reviews that are done pre interview offer. These schools get swamped, and I bet that a quick look at "numbers" yields more interviews than are probably deserved...and just as many applicants get passed over, or screened out, based on their numbers with not much attention paid to the whole person.
The bottom line is that not all schools will view this lack of US clinical experience equally, so these applicants may still get some good news from somewhere.
I did do the traditional hospital volunteering in the US as well as some stuff in homeless shelters and with the Red Cross. I'm working this year in the US and seeing patients every day. I think I must have failed to communicate those things effectively, so my advice to other applicants is to really stress your EMT/hospital experiences in your interview so that is what gets presented to the admissions committee. I'm pretty depressed about this still but I hope others can learn from my mistakes!