The following definition was assumed:
"A passive construction occurs when you make the object of an action into the subject of a sentence."
Therefore, the placement of the actual subject of the action as in a prepositional phrase keeps the logical subject as an object.
That is "by me," is simply a modifier in the sentence and does not determine if the sentence is active or passive.
Less objectivity is conveyed by use of "by me," however. It is understandable that this is an objection in scientific language.