Do you think its okay to...in an academic paper.?

Okay, So I'm per-reviewing a guy's paper for my english 102 cl, if I agree with something, or if I want to add some funny comments into it, do you think that would be okay? like he forgot to add a comma before a conjunction so I wrote conjunction junction, what's your function? or, he brings up how he was a senior in high school during hurricane katrina, and I mention that I was in 8th grade when it happened? I dont want to get in trouble, I just like to keep the comments light, cause I know a lot of people get kind of mad if you correct their paper a lot...cause its peer review. What do you think?