Sometimes it just comes down to numbers,
THink about it in sport terms, 13 and 14 year olds shouldn't be playin against fully (and sometimes over) developed adults in senior football, but if they know there stuff and willing to do it, they are allowed to play senior footy, same thing goes.
If the consultation is done, students, parents and schools are aware of the processes that need to take place for this to occur and the learning of others isn't affected then go ahead.
As a teacher I wouldn't leave when I'm in the middle of the lesson, but it's a great way to get out of staff meetings... (just trying to learn how to set off tone 7 inconspiciously now and get out of a couple more meetings...)