Hindsight is a wonderful thing.
If there wasn't any wake turbulence this would have been a low but very normal approach and landing and we wouldn't be discussing this.
The instructor would have been well aware of the danger but being an invisible force it can be impossible to see.
My instructor would have let me continue my approach as this instructor did and then brief me afterwards what I could have done better next time.
When you get quite a way through the syllabus your instructor should take a back seat and let you make your own decisions. Its an important part of learning.
This wasn't anybody's fault and we should all learn from someone else's misfortune.