he was riding behind the Prophet and he continued to recite the Talbiyah until he stoned the Jamrat.  

أَنَّهُ كَانَ رَدِيفَ النَّبِيِّ ﷺ فَلَمْ يَزَلْ يُلَبِّي حَتَّى رَمَى الْجَمْرَةَ  

the Messenger of Allah recited the Talbiyah unitl he stoned the Jamrat.  

أَنَّ رَسُولَ اللَّهِ ﷺ لَبَّى حَتَّى رَمَى الْجَمْرَةَ