The port layline at A is already dangerous, you have somebody forcing a controlling position and a few starboards coming in and somebody could die real easy in these boats.
The rules don't prevent you from sailing into an untenable position.
Eric - for "room" do they have be able to be clear to go any direction (tack or duck)?
The rules don't define "avoiding action". Nor do they stipulate how a boat must choose which actions to take. Check the definition of "keep clear", as well as ISAF Case 50 for clarification.
The argument that Artemis kept clear because Groupe Edmond could have waited for Artemis to complete her tack, and then have room to tack (in a seamanlike way) herself is a real stretch here. I don't believe it would prevail in a protest hearing. All GE has to say is that she had a reasonable and genuine apprehension of collision (validated because she could not avoid contact despite having taking prompt action), and that her snap decision was that a crash-tack was too risky so she attempted a bear-away.
