Any questions of legality that might arise I think would be...

Any questions of legality that might arise I think would be about purchases made during the takeover period. My understanding is they can't buy at market during takeover period at a price higher than the offer - correct me if wrong.

Would be pretty hard to prove if an undercover deal was done eg company tells broker to accumulate to a limit price eg $1.05 and they'll make it worth their while after the takeover finishes eg buy at $1.06 or so. ASIC would have no hope.