-んじゃなかった

Hi,

I was watching Chihayafuru and in episode 1 of season 3 (21.06), the character says “知らないよ。あのおにぎりを上げるんじゃなかった。” and it is translated as “I don’t know. Jeez, I shouldn’t have given you those rice balls”.

My question is, is 上げるんじゃなかった similar to あげらなければよかった in that they both mean “I shouldn’t have given” or is the translation taking a rather liberal approach? Because I only knew about the latter.

Thanks,

by Vadzianyk