Aut cum scuto aut in scuto
If it's stupid but it works, it ain't stupid.
That would never pass for high reliability soldering.
An example of a FEM or "Field Expedient Modification". The ability of the individual to adapt gets the mission accomplished.
Necessity is the mother of all Alabama Engineering...
I've seen worse, not saying it's great but I have seen worse.
Soldering to chrome plated objects usually requires acid flux. So long as he neutralized and cleaned it after the fact, he should be good. Otherwise, ...
....in the absence of a female-female 1/8" connector jack.
I've seen crap like that on million $ yacht's navigation equipment.
Only one problem I see, he soldered a stereo plug to a mono plug but yes it will make sounds.
Kludging is the bastard stepchild of necessity.