ATC here. It will depend on the layout, like are there water towers, etc. The pilot absolutely did his research of course & approach plates will have the Minimum Safe Altitude (MSA) on there. The problem here is, if it wasn’t pre-arranged with ATC, this counts as a deviation. I know people will say “screw it” to the first reason, but there are noise abatement & MSA rules to follow. The maneuver itself could have been perfectly safe, but if you don’t let anyone know about it, that’s the problem. Safety of aircraft is the pilot’s responsibility; safety of airspace is ATCs.

Commercial aircraft tend to do instrument approaches, though, on good weather days, they could ask or ATC could offer a visual approach or an ILS. More often than not, in the summer, Approach will clear an aircraft for either an ILS or visual approach for runway 17 & ask the pilot to tell me in the Tower what they choose to do. I have received requests of slight deviations for whatever reasons & more often than not, I approve them for it, as long as it doesn’t break any minimums. So did this pilot not even say anything?! Pilots also know when the busier times are & won’t bother us with these shenanigans during those times.

As for South Africa, I can’t speak to that, I’m in Canada. Every country, every city has their own rules when it comes to noise abatement. Helicopters are able to fly low to do their jobs, civilian or military, but they all ask for approval prior to even leaving the ground.