Not a fail at all - it's a good shot... and if there's a yellowy cast maybe the light was... erm... yellowy!? If you can remember in your mind's eye what the scene looked like when you were there, you will be able to tell better than the rest of us what it should be
Re: sharpening - if you look at the image fullsize in Flickr you'll see quite a lot of artifacts where the sharpening algorithm thinks it has found an edge and has made it more distinct. But because the threshold was set (IMO) too high, it is turning dithering (think old newspaper colour prints - loads of dots) into edges. Look at his chin, his right cheek (left as we look at the reversed image) and around his right eye - there are plenty of telltale signs.
The trick I find (and I'm no expert) with sharpening is if the image looks "processed" then it's gone too far. I also try to be equally careful with noise reduction - too much and an image becomes plastic, meaning you then start to over-apply sharpening to get the edges back... a vicious circle of processing! As an example of "tough" conditions, here is a photo I took at 4.30am (before sunrise) through a window from a dark room with a zoom lens (albeit quite a decent quality one) - in order to get the shot I needed ISO3200, so it is horribly noisy. It's full of detail (grass, deer fur) so I was between a rock and a hard place. This is the best compromise I could manage between extracting detail and reducing noise, without introducing artefacts - it's not great by any stretch:
https://www.flickr.com/photos/123807334@N03/14648410526/ (choose original size to see the poor quality).
Conversely, my "rich" picture is no great photo by any measure, but taken at ISO 80 it needs virtually no NR. This makes sharpening easier - I actually used a high sharpen 40 in LR (more than the high ISO image, which was 35) but also a high masking threshold at 60 (and probably should have gone to 70)... but there are very few artefacts. (As an aside, the reason for the high sharpening was because I felt the cookies were more OOF than I wanted because of my DOF choice so I was trying to rescue...)
Edited to add: everything I've said could be complete and utter mince... I'm a newbie to all this really but it's what I find works "for my eyes". Which could, of course, be bad eyes!
Edited again to add: I have to look at the image 1:1 to check for sharpening/NR artefacts... often they don't show up as easily when zoomed out. Having said that, I could see them on your otherwise lovely photo at forum resolution so I guess it's horses for courses! (Flickr sometimes does strange things, too...)