No, I didn't think you were saying that. But this seems strange to me:
ABC News has also learned that Clark sent a text message to Le early Tuesday, Sept. 8, requesting a meeting to discuss the cleanliness of the the cages of the mice in the research lab.
http://abcnews.go.com/US/annie-le-suspect-raymond-clark-released-giving-dna/story?id=8588970
What could make sense is if she was leaving some mess from her experiments in the cages...or that she put too much equipment in the cages and it was preventing him from (somehow) doing his job. He would probably not be expected to clean up after her. But he would be expected to clean up after the mice.
Getting to motive, I imagine that there must an animosity between the techs vs the academics..and he felt it intensly. He used the "rules" (protocols) to get back at the people he resented most. So, he called Annie to task for some rule he felt she had broken and she went with the protocols to defend herself. Like many animal lovers, he justified his rage by his "love for animals", by saying to himself, JH and family "no one should treat a defensless animal that way". If it does come out this way, I would not be surprised if he becomes a hero in the eyes of some extreme animal activists.
Until todays press conference when the chief of police denied that there was any romantic relationship between Clark and Annie, I would have bet they were ex-lovers. After all, Tuba told us that Annie was not in harmony with her marriage. That sounds to me that she might have had an affair and was not completely free from it. His ex-girlfriend claimed he raped her when she tried to break up with her, so if he had an affair with Annie, he might have done the same and then killed her.
But the Chief seemed so convinicing today that there was no romantic involvement between the two. So, I am going for the scenario above.