This hadith has been narrated on the authority of Shuʿba through another chain of transmitters. But there is no mention of "I personally saw him" in this hadith.
عَنْ شُعْبَةَ بِمِثْلِ حَدِيثِ مُعَاذٍ وَإِسْنَادِهِ وَلَمْ يَذْكُرْ أَحَدٌ مِنْهُمْ فِي الْحَدِيثِ شَهِدْتُ حُذَيْفَةَ غَيْرُ مُعَاذٍ وَحْدَهُ إِنَّمَا قَالُوا إِنَّ حُذَيْفَةَ اسْتَسْقَى