Point from shia fiqh of salat

Sheikh of shias in ahadeth, Muhammad al-Kulayni narrated in his “al-Kafi” (3/18):

14 – علي بن إبراهيم عن أبيه عن ابن أبي عمير عن ابن أذينة عن زرارة قال : توضأت يوما ولم أغسل ذكري ثم صليت فسألت أبا عبد الله ع فقال : اغسل ذكرك وأعد صلاتك .

From Zurara: “One day I have made an ablution, and didn’t wash my penis, then I have prayed, and I asked Abu Abdullah (alaihi salam) about this, he said: “Wash your penis, and repeat your pray”.

Hadith hasan per Majlisi and saheeh per Bahbude.

Kulayni also narrated (3/18):

15 – محمد بن يحيى، عن أحمد بن محمد بن عيسى، عن الحسن بن علي بن يقطين، عن أخيه الحسين، عن علي بن يقطين، عن أبي الحسن (عليه السلام)  في الرجل يبول فينسى غسل ذكره ثم يتوضأ وضوء الصلاة؟ قال: يغسل ذكره [يعيد الصلاة] ولا يعيد الوضوء.

From Ali ibn Yaqtin from Abul Hasan (alaihi salam) about a man who pissed, then forget to wash his penis, then he made an ablution and prayed. He (imam) said: “Let him wash his penis (repeat pray) and not repeat ablution”.

Hadith saheeh both per Majlisi and Bahbude.

Let us examine these saheeh ahadeth.

1) Man forget to wash his penis. Does it invalidates his ablution? Apparently from those two ahadeth – no. Because imam didn’t order him to renew his ablution.

2) His first pray for imam was void, so he ordered him to repeat it.  If that didn’t invalidate his ablution, how that could make his pray void?

Source: http://www.alrad.net/hiwar/tkous/53.htm