It's not accessing the package's symbol table (which is what I interpret from your "... the packages's hash ..."). It's simply fully qualifying the $VERSION variable. It can't do my or local because $VERSION needs to be a package variable so that it can be accessed outside the package. This is simply one of the possible ways to declare this.

They could have done any of the following:

• $PackageName::VERSION = whatever;
• our $VERSION = whatever;
• use vars qw( $VERSION ); $VERSION = whatever;