He wasn't trolling..?
You said bad grammar was a trait of a 'choob'.
He pointed out that it isn't - he just can't be bothered to spell check on a forum where grammar/spelling can typically be disregarded as long as the post is legible, after all this is no spelling bee, everyone makes mistakes - Even you;
(Keep in mind you said grammar, not spelling; However, he has made no grammatical errors, therefor it is safe to say you are referring to his spelling)