If anyone thinks that the author was interested in comparing Java and Perl's garbage collection, that was a misunderstanding.

The author's real interest was to compare the memory management implementation between Java and traditional c/c++. Perl was merely mentioned as an example of large c programs.

Whether the quoted source was based on Perl 4.10 or Perl 5.8 was not related to the interest of the author, and does not make a difference to the point the author was trying to make (all he cares is to pick some large c program, although 5.8 is totally different from 4.10 to Perl users, but that's irrelevant in that context). That was why an article in 1994 can still be quoted as a meaningful reference.