Most of the hashbang test262 tests are "raw" tests -- that is, the script files are supposed to be run without alteration -- because it's crucial that "#!" (or an unreasonable facsimile of it being tested to not work) appear at the very start of the test. The raw hashbang tests that are expected to fail are no exception.
However, jstests as run in the shell encode "this test is expected to fail" using a
// |reftest| ...
comment at the start of the file -- conflicting with "#!" or an unreasonable facsimile of it.
We don't currently have a way to import raw-and-negative tests. We need one in order to run (and not skip) a fair number of the hashbang tests.