What I'm assuming he means by it is that the review came across very subjectively. By that, he means that it came across as more of an opinion than an album review. The aim for the review is to analyze a record in a way that people who like the genre/band, people who hate the genre/band, and people who may have never heard of them all get the same idea for the album in your writing.
I guess in a way you want to write an album review the same way you would write a lab report: Cut and dry with the information clearly presented. Thats not to say you can't put your personality into it, its just that the album should be the focal point.
The best way to tell if its subjective/objective is to see what type of person you write in. If you write in first person, it will be subjective. If you write in third person, it will be objective.
For example, you say:
"The song progresses and you hear the first true breakdown and Mike screams, "No end to my burden!". This early in the record I knew they meant business."
If you wanted to write this objectively, you would probably want to say something like:
"When the song reaches its apex, Mike bellows, "No end to my burden!", leaving any listener helpless to the sonic force that will cause the earth to tremble."
Notice how I kind of said the same thing, yet have taking myself (or technically, yourself) out of the equation.
Hope this helps, I've been meaning to get back into writing reviews, its been like 1-2 years. Maybe soon.