For the record two of the earliest complete descriptions of the Roman liturgy we have, the
first Ordo Romanus (7th-8th c.) and the
St. Amand Ordo (late 8th c.) also seem to suggest that facing the people and facing the east are two different things.
Now when
As it was in the beginning is said, the deacons rise up in order to salute the sides of the altar, first two, and then the rest by twos, and return to the pontiff. And then the latter arises, and kisses the book of the gospels and the altar, and, going to his throne, stands there facing eastwards. …] When they [the choir] have finished [the Kyrie], the pontiff turns himself round towards the people, and begins,
Glory be to God on high, if it be the season for it, and at once turns back again to the east until it be finished. Then, after turning again to the people, he says,
Peace to you, and once more turning to the east, says,
Let us pray, and the collect follows. At the end of it he sits, and the bishops and presbyters sit in like manner.
…] At the end of the [post-communion] anthem the pontiff rises with the archdeacon and comes before the altar and says the post-communion collect, facing eastwards. For at this part of the service, when he says,
The Lord be with you, he does not turn to the people.