Ibn A'idh (may Allah have mercy on him) says that a group of three men from the Companions of the Prophet (peace and blessings be upon him) (may Allah be pleased with them) came to the mosque while the people were praying Asr, having already finished the Zuhr prayer. They prayed with the people. When they had finished, they said to one another: "How did you do it?" One of them said: "I made it Zuhr, then I prayed Asr." The second said: "I made it Asr and after it I prayed Zuhr." The third said: "I made it the greeting of the mosque (tahiyyat al-masjid), then I prayed Zuhr and Asr." And none of them found fault with another.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5112