Yesterday one of the priests in our ward had to repeat the sacrament prayer. When that happens, I imagine other congregants do as I do – we say a silent prayer that they young man can find his voice and read the prayer correctly to avoid embarrassment.
Few prayers are delivered word for word in the church, but some that are related to ordinances are, including the sacrament prayers.
I remember two specific experiences that have colored my memories. The first was when I was newly called Teachers Quorum president. Right after a meeting (it might have been a morning Sunday School meeting – we had those back then), I was given a stern talking-to by a newly ordained priest who had to repeat the prayer. He hadn't made a mistake – he read the prayer right from the card – except that he read the wrong prayer. As we teachers set up the sacrament, we had not taken care to be sure the right prayer was facing up on the card.
At the time, I thought (but did not say out loud – this guy was a weightlifter and I was certainly not), "You could check the prayer before your start!" But in the intervening years, I thought he was right: I should magnify my calling and perform my duty as best I can; I should do whatever I can to assist others in performing their duties.
When I became a priest, I worked hard to avoid having to repeat the prayer. I practiced it before I gave it the first time. And the priest who "trained" me (the same one who had the inverted card a year before) recommended I start with the prayer on the bread so I wouldn't have a swarm of deacons around the table distracting me. I may have had to repeat a prayer or two as a priest, but I don’t remember having to do so. In my second memory, I was rescued by my companion:
I was in the MTC – well, I think it was still the LTM officially, but we were in the "new" buildings where the MTC is today. Our branch was made of all German-speaking districts and we did the sacrament prayers in German. Sometime during the course of our stay my companion and I were to bless the sacrament. I practiced the prayer for a couple of days ahead of time. And when the time came, I read the prayer slowly and carefully, and started to stand up when my companion whispered, "Amen." In my zeal to get all those complicated German words right, I'd forgotten the last word. I fell back to my knees, said Amen, and stood. My pride was a little bruised, but my companion was kind about it.
There is value in learning exactness in small things like sacrament prayers as it attunes us to exactness in larger things.