Machine learning for object states
To me this problem looks similar to language modeling: a model is trained on a large amount of sequences, and then it can predict the probability of any input sequence. In your case a low probability would indicate an abnormal sequence.

My background is in NLP that's why I think language modeling, but I guess the same techniques are used for other problems as well. The fact that you have transitions and states suggests Markov Models, for which there are known methods for inference and estimation. So maybe you could design a more specific kind of model for your case and use something like the Baum–Welch algorithm.