Suppose a man bargains to enfeoff me, as in our case here, and he afterwards enfeoffs another, and then he re-enters [i.e. on the first feoffee] and enfeoffs me, and the other ousts me. Now here the action of covenant may not be brought, because he has at last enfeoffed me according to his covenant, and yet the deceit remains upon which an action may be based. Wherefore it does not always follow that where there is a covenant the action of deceit will not lie.
Source: wiktionary