AIO about my friend misunderstanding something, but him not accepting it

My friend (John), is watching Fate/Zero (I have watched it, he has never). He is on episode one.

The show starts of with showing us a family of mages and blah blah blah. The scene ends with it zooming out the castle, the title call “Fate/Zero”.

The next scene starts. At the bottom saying “3 Years Ago”, and shows us this guy, Kotomine Kirei, talking about how he will train for the upcoming war for the full 3 years he has. the scene ends.

The next scene starts. At the bottom it says “1 year ago”, and it shows us this different guy, however this guy is saying how he only has 1 year left to train to become strong for the SAME WAR.

For some reason, John misinterpreted it as 1 year ago, FROM the 3 years ago. The question he asked me was “why does he need to train in 1 year when has 4 years, while this guy is training for 3”

I explain to him how that it doesnt mean that, and how it doesn’t even make sense from the context. However he blames that its the way it was phrased that confused him.

I give him multiple examples, saying “if i said 100 years ago i did this. 50 years ago i did this. are you going to assume im talking about 150 years ago?” However, he claims that this is not the same case.

My second example was “i was born 20 years ago. 19 years ago i moved to germany.” He then says this doesn’t make sense because how will someone born 20 years ago move to germany 39 years ago.

While he is giving excuses, he keeps telling me that I am “rage baiting” and that “i’m not getting him.”

I truly give up and say “why are you still talking, you are literally wrong” (talking about the show), which then he replies “bros acting like he needs to reply.” I reply “F*** you then.” he then says “How are you gonna get mad at me.”

Am I overreacting when he asked for help in something he didn’t understand, me giving him the answer, for him to proceed to give excuses, and then at the end say that I didn’t even need to reply?