פירוש על עבודה זרה 61:8

According to R. Elazar, if one wants to guard, for instance, one’s food, such that it remains kosher, one seal around the package is enough (I know—on the airplane they put two seals). The exception is wine—wine must be guarded by a double seal. R. Yohanan says that one seal is always sufficient.

This is an unusual use of the term “and they are not arguing” because in the end R. Elazar and R. Yohanan do argue. R. Elazar holds like the rabbis—a seal is not sufficient to protect wine. R. Yohanan holds like R. Eliezer—a seal does guard the wine.