Blocking D Actions

Can a target of a D action that's a Minion, block a D action that’s directed against themselves?

For example, I was playing a game recently and Millicent Smith was on the table.
Player 1, (with Millicent Smith) played Haven Uncovered on an untapped Lambach (player 2).

After the Haven was played, Player 1 announced an attack on Lambach with one of her vampires.

Player 2 then used Lambach to block the Direct Attack against himself enabled by the Haven, invoking Millicent Smith to destroy Player 1’s attacking vampire.

Nothing in the rules (that I’ve found) expressly forbids blocking D actions with the target of the D action, so long as the target is Ready. It still seems weird to me. What do you guys think?

Ankha,

Thanks for the reply. Browsing through some other posts here I was beginning to suspect that, but it's great to have confirmation.