«وَإِنْ وُجِدَ مَتْنٌ يُرْوَى مِنْ حَدِيثِ صَحَابِيٍّ آخَرَ»
If comparable wording is transmitted as the report of another Companion.
Such a supporting report is called a shahid. The condition is not merely that one narrator differs: it is that the supporting account reaches a different Companion from the Companion of the initial report.
A shahid may resemble the initial text in wording as well as meaning, or only in meaning. This distinguishes the Companion-level separation from the question of textual resemblance. With the same Companion and another lower chain, the usual name is mutaba‘ah.