Dummett was sent on at half-time to lead the charge against Everton with the Magpies 2-0 down.
Benitez said: "I said the other day that he's someone that you can trust.
"He can give you always a seven, sometimes and eight, sometimes a six, but always he is around there.
"It's difficult for him to give you a 10, but it's difficult for him to give you a one.
"When you have someone that you can trust as a manager, if you put him on the pitch, you know exactly what you can expect from him, and that he can manage the situation in a line of five and after in a line of four."