Genetic factor. Hamilton's research says that the ones that did get pattern baldness from the testosterone supplement had family history.
dHT factor. Dht in high concentrations inhibits wnt. In medium concentrations maintains wnt.
Pattern factor. A single high glucose meal inhibits endothelial vascular function, and Enos, constricting both ways. Long term NO inhibition builds vascular smooth muscle, making vasodilation even less likely. AR upregulation disrupts glucose homeostasis, reinforcing vasoconstriction where dHT is accumulating. (Both from inflammation and disfunctional circulation). The pressure of scalp plus this vasoconstriction plus genetics starts to build a cycle.
(Can't be bothered detailing more sorry).
Working on recovering from it now, it's a challenge as to what is recoverable, and whether androgens are a problem if constant NO vasodilation is achieved.
I actually found abiraterone to be counter productive, and the common side effect of hypertension would support that.