Can he wipe over his socks if he put the right sock on before washing his left foot?
Question

                Some people wash the right foot in wudoo’, then put on the sock, then they wash the left foot and put on the sock. If they do wudoo’ after that, is it permissible to wipe over the socks?.
Praise be to Allah.It is better and is more 
    on the safe side for the person doing wudoo’ not to put on his socks until 
    he has washed his left foot, because the Prophet  (peace and blessings 
    of Allaah be upon him) said: “When one of you does wudoo’ and puts on his 
    khuffayn, he may wipe over them and pray in them, and he need not take them 
    off if he does not want to, except in the case of janaabah.” Narrated from 
    Anas (may Allaah be pleased with him) by al-Daaraqutni and by al-Haakim who 
    classed it as saheeh. 

    It was narrated from Abu Bakrah al-Thaqafi (may Allaah be 
    pleased with him) that the Prophet  (peace and blessings of Allaah be 
    upon him) granted a dispensation to the traveller for three days and three 
    nights, and to the non-traveller for one day and one night: if he purifies 
    himself and puts on his khuffayn (leather slippers or socks), he may wipe 
    over them. Narrated by al-Daaraqutni and classed as saheeh by Ibn 
    Khuzaymah. 

    It is narrated in al-Saheehayn from al-Mugheerah ibn 
    Shu’bah (may Allaah be pleased with him) that he saw the Prophet  (peace 
    and blessings of Allaah be upon him) doing wudoo’ and he wanted to take off 
    his khuffayn. The Prophet  (peace and blessings of Allaah be upon him) 
    said to him: “Leave them, for I put them on when they (my feet) were in a 
    state of purity.” 

    The apparent meaning of these three ahaadeeth and similar 
    reports is that it is not permissible for a Muslim to wipe over his khuffayn 
    except when he put them on in a state of full purity. The one who puts his 
    khuff or sock onto his right foot before washing his left foot is not in a 
    state of full purity. 

    Some scholars are of the view that it is permissible to wipe 
    over the sock even if the person put his right foot into the khuff or sock 
    before washing his left foot, because in each case it is done after washing 
    the foot. 
But the first view is 
    more on the safe side, and it is more apparent based on the evidence. So the 
    person who has done that should take off the khuff or sock from his right 
    foot before wiping, and put the sock back on after washing the left foot, so 
    that he avoids an area of scholarly dispute and will be on the safe side 
    with regard to his religious commitment. End quote. 

    Shaykh Ibn Baaz (may Allaah have mercy on him). 

    Majmoo’ Fataawa Ibn Baaz, 
    10/116 

    Another indication that it is not permissible to wipe over 
    the khuffayn unless one put them on when in a state of full purity is the 
    report narrated by Ibn Khuzaymah and al-Daaraqutni from Abu Bakrah (may 
    Allaah be pleased with him), according to which the Prophet  (peace and 
    blessings of Allaah be upon him) granted a concession to the traveller for 
    three days and nights, and to the non-traveller for one day and night, 
    allowing them to wipe over the khuffayn if they put them on after purifying 
    themselves. Classed as saheeh by al-Khattaabi. Al-Bayhaqi narrated that 
    al-Shaafa’i classed it as saheeh and al-Nawawi classed it as hasan. 
    Talkhees al-Habeer, 1/278. 
See al-Majmoo’ by al-Nawawi, 1/541.