https://courts.delaware.gov/Opinions/Download.aspx?id=349400
Just skimming quickly, he distinguishes between a sales process claim and a disclosure claim, with the latter being a pure offense to SH's voting rights. He finds the offense to voting rights alone is worth between 50 cents and $1 per share.
Which begs the question whether that analysis will also apply outside the sales context, like, when shareholders are asked to vote on a share issuance for the purpose of making an acquisition.
Like, this isn't a situation where a counterparty bribed an officer, or something, to get a deal done; here, TransCanada just cultivated the goodwill of the people it was dealing with and took advantage of their preexisting self interest and naivete.
The line between A&A and simply sharp dealing is not clear to me.
To put it another way, TransCanada did not create the situation that resulted in the fiduciaries' self interest; it's not even obvious TransCanada fully understood what it was. It simply took advantage of their eagerness to get a better deal.
To call that aiding a breach is ... well, seems odd to me, but again, I'm not up on the precedent.