Not really, if we read the entire paragraph:
"If another effect lets you roll twice and use the higher result when making an attack roll, this power has no effect on that attack. If an effect forces you to roll twice and use the lower result when making an attack roll, this power has no effect on that attack either."
Clearly, the term "this power" refers to Oath of Enmity, because it's written in the Oath's power description. If it meant the "roll again, take higher/lower" effect, it'd say "this effect".
