NOT doing so is ok for me, its not a major inconvenience, but i feel like there must be a big warning somewhere, maybe on the list interfaces page telling you not to edit more then one node simultaneously.
Actually i had a HUGE problem regarding the same case, i was creating regular (not admin) user for NPM and while i was going through every detail of it, i found something that i wanted to change on my admin account also (temperature units from F to C) so i opened my admin account in another window, edited and than saved both accounts. Outcome was horrible, my built in admin account lost admin privileges and i had NO admin account on NPM not even one.
i Fixed it from database manager