All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The devil whispers to the son of Aadam (Aadam) things that harm him. He swore to sit in wait for him on Allaah’s straight path (i.e. to prevent him from it) and he swore that he will come to him from before him and from behind him and from his right and his left, and that he will tread any path to harm the son of Aadam.
He can whisper to a person to do a good thing and beautify it for him if this would distract him from something better than it. But he primarily wants to make the son of Aadam fall into disbelief. If he is unable to do that, he would try to make him fall into heretical innovations; if he is again unable to do so, he would try to make him commit major sins. If the believer holds fast to the Covenant of Allaah and the devil is unable to lure him, he would try to entice him into committing minor sins. If again he is unable, he would try to distract him with something that is less important so that he does not do what is more important.
If such a person is knowledgeable and is aware of all this, and the devil is unable to lure him, then the devil would try to make other people harm him.
Regarding what you mentioned, there is no apparent reason for the second person mentioned in the question to be harmed. It might be this person who is being whispered to and not the Imaam reciting the Quran. Shaytaan could be whispering to him that something caused the Imam to recite that part of the Quran, even though the matter happened by coincidence and was not caused by something. Shaytaan may also want the person to be distracted from something to his benefit or something that is better for him.
Allaah Knows best.