(a) A similar narration is reported through another chain. At its end it says that he (peace and blessings be upon him) said: "Then raise your head (from the second prostration) until you stand up straight."
(b) Imam al-Bukhari (may Allah have mercy on him) has also recorded this narration in his Sahih.
In the narration of Yahya there is no mention of the second prostration, nor of the sitting for rest after the second prostration, nor is the standing mentioned.
(c) And the standing is more fitting, because the pillars (arkan) are being enumerated, not the sunnahs. (And Allah knows best.)
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2767