Flags authorised in Kithgard Enchanter?

I was looking in levels that i already done to fool aroud when i noticed that in Kithgard Enchanter you could use flags instead of function to complete the level, witch isn’st supposed to be like that i think ?

Here’s some picture:


Only the green one is allowed, while the other ones are blocked.

I was wondering if it was just an error or it was supposed to be like that