Q 103

Let's have a look at the battlemagic perception spell:

Quote Originally Posted by Heroes of Battle
If you have at least 5 ranks in Spellcraft, you are also able to sense the use of any spell or spell-like ability within 100 feet, so long as you have line of effect to the caster.
With a Spellcraft check (DC 15 + spell level) you can even ascertain the spell being cast.
This determination happens quickly enough that you can attempt to counter the spell as a free action.
Am I right to think that, as written, it just doesn't work? You can't counterspell "as a free action" since free actions can only be taken on your turn, and another spellcaster isn't going to wait for you before casting his spell.

For this option to be any useful, it should allow counterspelling "as an immediate action", right?