You talked to a member of an Orthodox Church, which counts the commandments as in the LXX column in the
table in Wikipedia (the term "LXX" is somewhat misleading, for there is no numbering in the text, it is just that Greek Orthodox count in that way, other Orthodox churches following them).
The comparison of "A/C" (catholic) and "L" (Lutheran) is instructive: Both have essentially he same numbering, but their 9th commandment is different. This is due to the fact that Lutherans base their numbering in Ex 20, while Catholics base their numbering on Deut 5. Looking on the differences in text between these two versions of the Dekalogue makes clear there is no real difference, only superficial change in wording (e.g. word order). This means. that the 9th and 10th commandment of Catholics and Lutheran are really one, they have only nine commandments and artificially split the last one into two, which yields to different results because the word order of Ex 20 and Deut 5 is not the same there.
This is almost like the Jews, who speak of "10 words" (a term to be found in the Bible, unlike "10 commandments"), counting the Prologue ("I am he LORD, ...") as the first word, and then 9 commandments (2nd to 10th word).
The Samaritans add a 10th to the 9 commandments: Put the stones with the law engraved on the mountain where the blessing is spoken to the people (Deut 27:12-13) instead on the mountain where the curse is spoken to the people (against Deut 27:1-8) - remember Gal 3:10-12?
As to the reformed and other Protestants, you know how they count.
But is counting in another way the same as skipping?