The Baggies dropped two points at the Kassam Stadium to go four without a win having led for large parts through Karlan Grant’s fine strike on half hour.
But substitute Dane Scarlett headed in after a Will Vaulks long throw was flicked on two minutes into stoppage time at the end of a frustrating second period.
Part of Corberan’s annoyance was how his side were guilty at handing possession to Oxford – via a sloppy throw-in from Torbjorn Heggem in an attacking position of their own – shortly before the Yellows bagged for a share of the spoils.
“The feeling is exactly that one, that we have lost two points for different reasons,” said Corberan after his side sacrificed top spot with the late goal against in the early kick-off.
“The more obvious one was the game management in the last moments of the game. I think in these moments the only way you have to protect the result, when you have tried to create but couldn’t, is to extend more attacks to try to create and not to give the ball to the goalkeeper.