If one accidentally recited full Hallel on Rosh Chodesh, am I correct that no further action is needed?
What interruptions are permitted during Hallel? May one answer Amein to the brachos of those who received an aliyah, if one is still holding in Hallel? May one answer Amein to those who bench gomel?
You are correct no further action is needed although some would like to suggest that it doesn’t hurt to read the Hallel again without a bracha. The interruptions that are permitted during (full) Hallel are the same as those permitted during the Shemah. If he is between the paragraphs he can answer Amen to any brocho.
O:CH 422:4, 488:1, O:CH 59 Mishnah Berurah 18 , O:CH 66 Mishnah Berurah 23 Teshuvas Pischei Zutah O:CH 25