[OGo-Developer] Paranoid check in DirectAction+Resource?

[Adam Tauno Williams]

I noticed in DirectAction
+Resource.m/_dictionaryForResourceEOGenericRecord this bit of code:
--------------------------------------
results = [ctx runCommand:@"appointmentresource::get-by-globalid",
               @"gid", gid,
               nil];
if ((rLength = [results count]) == 0) {
  [self logWithFormat:@"No result found, but global ID is valid"];
  return nil;
}
if (rLength >= 2) {
  [self logWithFormat:@"Too many results for one global ID found"];
  return nil;
}
--------------------------------------

Is the "rLength >= 2" check generally necessary?  I thought that a
request by gid would return one object or none?  In what circumstances
can a request by gid return two or more objects?  (I get the difference
between using the key "gid" and "gids").