So sorry to hear about your partnership experience with your brother. I hope you guys were able to dissolve the partnership amicably. Sadly, that is often not the case.
Regarding the $30k as taxable income, it sounds like you need to get a second opinion from another accountant. Your current accountant may be right, but it would help your "peace of mind" immensely to have a different accountant provide their insight. You might just be able to pay them for an hour of consultation time. Oh, and don't tell your current accountant about your "second opinion" - it may hurt their feelings.
Either we did not get all the facts or your accountant did not.
If the parnership was dissolved 2 year ago did you form a new LLC or was it not technically dissolved? Since you paid $30,000 was this for assets or stock or were you just paying back a "loan"? I still can not figure out how it is income though. Seems like we only have 1/2 of the story.
to many unknowns (as noted by other posters already), if the original partnership was dissolved why are you buying his interest, if you transferred the interest to a new LLC and then purchased his interest then it should not be income to you.