It has nothing to do with science.
It is about the logic of his reasoning.
According to Christ, who is Reason personified, the divine Logos (the word Logos is a Greek word from which we get the word Logic, and to be for Reason is to be
prologoi, and to be unreasonable is to be
alogoi - St. Epiphanios of Cyprus in an amusing pun referred to an obscure heretical sect which rejected the Gospel of John, which is noteworthy for beginning a declaration of the deity of Christ and His incarnation, starting with “In the beginning was the Word, and the Word was with God, and the Word was God,” the logic of my friend
@MarkRohfrietsch is sound.
According to the the Gospel of John chapter 6:47-58 1 Corinthians 11:17-26 and the corresponding institution narratives in the three synoptic Gospels, at the Last Supper Christ our True God caused the bread and wine to be His Body, broken for many, and Blood, the Blood of the New Covenant, and instructed us to partake of His Precious Body and Blood for the remission of sins and life everlasting, and warned that those who refuse to partake of His Body and Blood that they would not inherit eternal life.
St. Paul in 1 Corinthians 11:27-34 further warned that those who partake unworthily, not discerning the Body and Blood of our Lord, put themselves at risk of sickness and death.
However for those who partake worthily, and the Eastern Orthodox and Oriental Orthodox, like
@MarkRohfrietsch ’s church the Lutheran Church of Canada, and its North American communion partners the Lutheran Church - Missouri Synod and the American Association of Lutheran Churches (which was formed of conservative parishes of the American Lutheran Church which did not want to join ELCA, and entered into altar and pulpit fellowship with the LCMS in 1989) are extremely careful to ensure that members who partake do so in a manner that is safe according to 1 Corinthians 11:27-34.
Thus, while not all Orthodox churches in the US used a shared spoon during the pandemic (I recall GoArch making use of individual spoons, which was extremely controversial and caused many people to leave either for another canonical church or for one of the many Greek Old Calendarist jurisdictions), among those that did there were no reports of any problems as a result
In my own parish, those who got it seem to have gotten it elsewhere; it was (is) a virulent virus, and in the secular world, spread by many means. Those in my parish that did get it (almost everyone) stayed away out of courtesy and respect for others. I worked in Automotive as an engineer, I had it (with positive tests) 4 times despite the vaccines and boosters I got... although, maybe they diminished the effect of Covid.
Pastor and I (served as Deacon) wore masks, as did our parishioners, and these were removed only during reception of the Eucharist. We were not careless. but we were 100% ready to reopen when we were legally allowed to.
Interestingly, when we (at work) stopped being so careful, it seems we got it less frequently. Timing? None of us got sick at Church.
In the US the illegal restrictions on worship were lifted by the Supreme Court in April of 2021 but some liberal denominations continued to impose restrictions on worship into 2022.