ASIC (the regulator) expressed concerns towards ISX's books and records.
ASIC (the regulator) advised the ASX that it was considering launching a formal investigation into matters concerning ISX.
The ASX (the market operator) then suspended ISX "In consultation with ASIC...pending the outcome...".
ASIC is investigating the same matters as the ASX as per ISX's own court submission. ASIC is running their own separate investigation and ISX is suspended pending the outcome of the investigation.
So explain to me why you think that only ASIC should investigate ISX? What possible logic did you use to base that belief on?