Addressing Rasulullah Sallalhualaihi Wasallam in His Absence – Is This shirk?

In this answer you have stated that Rasulullah sallalhualaihiwasallam was present when the blind man made the dua:

Hadith of Dua’a Via Nabi (S.A.W)

Notably we read that the same dua was also made years later when Sayyiduna Uthmaan ibn Hunayf [radhiallaahu anhu] himself taught this du’aa to someone AFTER the DEMISE of Rasulullah [sallallaahu alayhi wasallam]. This is the narration:

Abu Umaamah ibn Sahl ibn Hunayf [radhiallaahu anhu] reports that a person requested Sayyiduna Uthmaan ibn Affaan [radhiallaahu anhu] to fulfil his need. Sayyiduna Uthmaan ibn Affaan [radhiallaahu anhu] did not attend to him. The person complained to Sayyiduna Uthmaan ibn Hunayf [radhiallaahu anhu] about his plight. Sayyiduna Uthmaan ibn Hunayf [radhiallaahu anhu] told him to make Wudhu, go to the Musjid, offer 2 Rakaats of Salaat and recite the following Du’aa: ‘O Allah, verily I ask you and I turn to you through our prophet, the prophet of mercy (Rasulullah – sallallaahu alayhi wasallam). O Muhammad! Verily, I have turned to our Lord through you so that He may fulfil my need.’ The person then went to Sayyiduna Uthmaan ibn Affaan [radhiallahu anhu] who then [radhiallaahu anhu] immediately fulfilled his need and told him to return whenever he had any need in the future. (al-Mu’jamus sagheer vol.1 pg.184)

We read that this person addressed Rasool [sallallaahu alayhi wasallam] directly in this dua through the words “O Muhammad! Verily, I have turned to our Lord through you so that He may fulfil my need”. This incident took place AFTER the DEMISE of Rasool [sallallaahu alayhi wasallam].

1)Why would this individual address Rasool [sallallaahu alayhi wasallam] by uttering “O Muhammad! if Rasool [sallallaahu alayhi wasallam] was not physically present in front of him?

2) Is it not shirk if Rasool [sallallaahu alayhi wasallam] is addressed from anywhere but at the Rowdha Mubarak (even though I do appreciate that the supplication was made to Allah and directed to Allah)?