A question about "The Key of Theodorus" spell

Sirs, Ladies,

I would like to propose you a little problem I found in the spell "The Key of Theodorus" (City and Guild, page 78).

The Key of Theodorus
ReTe 10
R: Touch, D: Mom, T: Part
This spell magically opens any single lock. Regardless of the lock's complexity or quality, it falls open at the end of this spell. Since the locking mechanism is designed to naturally move in a single direction to lock and unlock it, this is a base 1 effect. The sixth century Greek inventor, Theodorus of Samos, is creeedited with creating the first locks in Mythic Europe.
(Base 1, +1 Touch, +2 Part, +2 for metal)

My question is why the Part target is considered +2, instead of +1 as per standard spell level guidelines (Part is only one step away from Individual, the base target for spells)?
Following the standard spell guidelines this spell should be a level 5 instead of a level 10 unless I'm missing something, but I also checked errata and I haven't found any useful information.

Thanks for your attention.

Not sure, but +1 magnitude for complexity would make the level right? :slight_smile:
It seems a fiddly and precise action, though maybe a finesse roll would be better...
cj x

Looks like a typo. The spell description indicates that the base level has been chosen because "mechanism is designed to naturally move in a single direction", so I don't think extra complexity is warranted here.