Currently the Reset Password page seems to be asking the user to either enter his Username or his Email address to get a temporary password. Allowing both choices is helpful but the way the requirement is specified could have been better. In some cases the user is likely to type both the Username and Email address without reading the text that informs the user that one is enough.
Merging the two fields into a single Username or Email address field and allowing the user to enter either in the same field. I think that would be a direct way to express this requirement. It's just a suggestion. A few screenshots of other websites expressing a similar requirement could be found below.
- GitHub Sign In page
- Edmodo Account recovery page
- Twitter Password reset page