Why is the complex [Co(ox)3]3- inner orbital and diamagnetic, even though oxalate is a weak field ligand?

Question

In a standard textbook for class 12, it was written the the complex Tris-(oxalato)-cobaltate(III) was a diamagnetic inner orbital complex. However, in J.D.Lee, oxalate is a relatively weak field ligand. How, then, is it possible?

Answer 1

I think the textbook was wrong.
The complex should be high spin
Have a look at
http://chemeducator.org/sbibs/s0010002/spapers/1020115dm.htm

Answer 2

(sound of crickets in background)