What was Kaldor’s argument against Hayek?

I remember seeing it some time ago, people using Kaldor against Hayek and saying that he debunked the Business Circle Theory.

I did read about it on a book recently but this part was quite… Small and summarized.

According to what I have seen his argument is that Hayek presupposes that capital is homogeneous?

This is very weird, first because there are no assumptions on Austrian Economics, second because on Austrian Economics capital is heterogeneous. So it seems like a huge strawman.

Am I understanding the argument wrongly?