As Jimmy points out, it isn’t hard (after recent amendments to the Act) to use money from both accounts, to carry out a job, and not reimburse the amounts exactly, but to swap some money from one account to the other. But if not reimbursed exactly, the Owners need to approve this within 3 months at a general meeting. A building might ignore the 3 month deadline if they believe the owners would approve this anyway, at the next AGM say – especially if the amount in question is small relative to the overall financial position of the building.
Also, the use of both accounts might be valid. Repairs are generally paid for from the Administrative fund. But improvements are generally paid for from the Capital Works fund. So, for example, if a window is damaged and replaced, and it was an old window without safety glass, the new window must have safety glass, which can be considered as an improvement, so (partially) a CW expense. Or if the building’s front door is replaced with a better one, then some of the cost could, or perhaps should be a CW expense, the proportion depending on the replacement/improvement factor.
And no-one seems to be too worried about using the “right” fund – the main issue is with investors, who have different tax claims whether there a Admin/CW source – they care! But generally only if the amounts are significant when spread among lot owners.
In your case, it may be a better solution to propose a motion a the next AGM (or an amendment to the motion setting the amounts of levies), to increase the CW levy, and perhaps reduce the Admin levy correspondingly.