Can a devotee get angry at the Guru?


Yes, a devotee can be angry, no problem. It is very safe to be angry with the Guru. 

Tell me, does anger ask you before it coming? No! You get angry and then later on you feel guilty; I should have not gotten angry. 

So don’t try to justify your anger at that time. You got angry because at that time you were ignorant, never mind, move on!