Sorry, that one's (especially since it's just a Year) is a stretch.
There IS a concept called beneficial ownership.
Where, under the code, if the person bears the benefits
of ownership[ they can deduct mortgage interest
taxes, etc IF they paid.
would likely say that this was transitory ... and that what the roommate did was gift or loan the money to the actual owner.
IRS has actually loosened, if you will, the interpretation of IRC section 199 (but this is as it relates to an ongoing issue where, say a manufacturing plant is able to deduct for a facility not actually owned, but leased,.
This one would likely be called a transitory situation.
If the roommate did this for several years and really took on ALL of the burdens of owning the property, and enjoyed ALL of the benefits just as under adverse possession, with real property title, THEN you'd have a stronger case.
So sorry, but in my opinion this situation wouldn't warrant... the beneficial ownership (sometimes called the substantial ownership) argument.
Hope this helps