Is the dimethylglyoximate anion ambidentate or not? In class, my professor said that dimethylglyoximate is a special ambidemtate ligand that can donate lone pairs via both nitrogen (which it normally does), and oxygen (very rarely).

On googling whether it is ambidentate or not, I didn't find anything. Can anyone cite an example where dmgH is donating lone pairs of electrons via oxygen and not nitrogen?

If this doesn't exist, can someone confirm that dmgH is not ambidentate?
I'm not sure if this example qualifies as an example for dimethylglyoximate acting as an ambidentate ligand, because it, for me, is more like bidentate. Nonetheless, I'm presenting this example here only because both nitrogen and oxygen are donating lone pairs within the same molecule. See trinuclear copper complex below (ref: doi.org/10.1107/S160053680301331X):