I think the concern is that Paragraph 145 of AL opens with “Experiencing an emotion [passions or passion of the soul] is not, in itself, morally good or evil” which then references Thomas Aquinas, Summa Theologiae I-II, q. 24, art. 1. However, this is actually articulated as Objections 1 and 3 to which Thomas replies to the contrary. Part of Thomas Aquinas’ answer to the objection is as follows: ipsae passiones, secundum quod sunt voluntariae, possunt dici bonae vel malae moraliter. Dicuntur autem voluntariae vel ex eo quod a voluntate imperantur, vel ex eo quod a voluntate non prohibentur (“The emotions themselves, inasmuch as they are voluntary, can be called morally good or bad. And they are said to be voluntary inasmuch as they are commanded by the will, or else because they are not checked by the will.”) This is where Father Thomas Crean states that there exists a serious mistake in the text of Amoris Laetitia, since certain emotions [passions] can rise by themselves to the level of mortal sin, for example, certain kinds of deliberate anger and sexual desire. It is dangerous to give the impression that only outward acts can be morally good or evil. AL does not clarify that Aquinas rejected the statement made in the opening of 145.