Yet another XY Problem ;-/

Rather than copy-pasting some sloppy details, you could have created some basic test case in order to demonstrate your claim. In the process, you / your friend could have "discovered" that there was no tie related problem whatsoever.

Without any code to review, there's not much that I can add to what ikegami already said, but I'm under the impression that your friend forgot one more thing, tie's return value:

tie VARIABLE,CLASSNAME,LIST
This function binds a variable to a package class that will provide the implementation for the variable. VARIABLE is the name of the variable to be enchanted. CLASSNAME is the name of a class implementing objects of correct type. Any additional arguments are passed to the "new" method of the class (meaning "TIESCALAR", "TIEHANDLE", "TIEARRAY", or "TIEHASH"). Typically these are arguments such as might be passed to the "dbm_open()" function of C. The object returned by the "new" method is also returned by the "tie" function, which would be useful if you want to access other methods in CLASSNAME.