Consider the case where the grad student, acting alone and not as part of an officially sanctioned project, invented something awesome using some resources from MIT like an internet connection and lab space. How eager do you think MIT would be to say "well, we didn't endorse anything you did, so you own the entire IP rights to everything; we want no piece of your new startup" ? Or the student discovers a flaw that gets a lot of press attention; how eager is MIT to feature the work saying they supported it, as opposed to saying "it was all unendorsed." Hint: both of these have happened many times, you can look up the relevant MIT policies, and you can ask people about how it went. MIT benefits immensely from "unendorsed" (i.e. implicitly endorsed after the fact) activities conducted on its campus.
Do you now see why it's ethically questionable for MIT to try to wash its hands off when the same researcher's exploration incurs some legal costs?
M.I.T. OWNED
(a) Patents, copyrights on software, maskworks, and tangible research property and trademarks developed by faculty, students, staff and others, including visitors participating in M.I.T. programs or using M.I.T. funds or facilities, are owned by M.I.T. when either of the following applies:
(1) The intellectual property was developed in the course of or pursuant to a sponsored research agreement with M.I.T.; or
(2) The intellectual property was developed with significant use of funds or facilities administered by M.I.T., as defined in Section 2.1.2.
(b) All copyrights, including copyrighted software, will be owned by M.I.T. when it is created as a "work for hire" as defined by copyright law, (see Section 2.1.3) or created pursuant to a written agreement with M.I.T. providing for transfer of copyright or ownership to M.I.T.
INVENTOR/AUTHOR OWNED
Inventors/Authors will own patents/copyrights/materials when none of the situations defined above for M.I.T.-Ownership of intellectual property applies.
[...]
M.I.T. does not construe the use of office, library, machine shop or Project Athena personal desktop work stations and communication and storage servers as constituting significant use of M.I.T. space or facilities, nor construe the payment of salary from unrestricted accounts as constituting significant use of M.I.T. funds, except in those situations where the funds were paid specifically to support the development of certain materials.
Do you now see why it's ethically questionable for MIT to try to wash its hands off when the same researcher's exploration incurs some legal costs?