We don’t know what actually happened. We are responding from third-hand information. So let’s talk theoretically, which we can. If a priest were to say “that’s bullshi_” in the confessional, it would depend on the context & the audience. If the penitent were a guy, who was also using earthy language, and said penitent were trying to excuse/rationalize an obvious grave matter, it could theoretically be a helpful slap-upside-the-head for the priest to issue a wake-up call to said penitent; it could be loving, in other words. It would also depend on the tone. If he was angrily interjecting a negative tone into the conversation, it would probably not be helpful. OTOH, if the priest was leading the penitent toward more honest self-evaluation, that is in fact one of the purposes of the sacrament. We try to make a good examination of conscience beforehand, but sometimes we are on the one hand too scrupulous, at other times frankly not disciplined enough. I would hope that a priest would use the right particular judgment. We don’t know directly about this occasion.