After scalar tie ...
$h->{FOO} = foo
$a = BAR
$a tied? TieTest=HASH(0x13c8dc)
h->{FOO} tied?
tie for reference SCALAR(0x102efc) = TieTest=HASH(0x13c81c)
tie for reference SCALAR(0x13c8d0) = TieTest=HASH(0x13c840)
After reference tie ...
$h->{FOO} = foo2
$a = BAR2
$a tied? TieTest=HASH(0x13c81c)
h->{FOO} tied?