Shield not reacting to cutthroat attack

[hoget10]

Unless I'm missing something, in game 115224630 I was incorrectly not able to react with shield to prevent cutthroat discarding:

For example:

k plays a Cutthroat.
h discards a Copper, an Estate, and a Doubloons.
h reacts with a Shield.

(there was no react popup or option to click the card prior to discarding)

[Ingix]

It's a bug, correct. The Cutthroat was reckless, and the way the Reckless mechanic is implemented has as a consequence that  the first "attack part" always happens  and the second can be prevented with the usual cards (Moat, here Shield).

It's a known, not yet fixed bug