Does the ruling of seeking مدد (aid/succor) from the dead and from those who are alive but not present—which is shirk (polytheism)—apply to someone who jokingly said to a friend via a social media site, "Madad, O so-and-so," intending to seek help from him in something he is capable of? And what is the ruling concerning the other colleague who described that as shirk?

Seeking help and succor from other than Allah in matters that none but Allah can do is polytheism (shirk (definition)). However, seeking it in matters that a created being can do is not shirk. And "madad" (succor) is assistance, and seeking it from one who is capable of providing it is not shirk, whether the request is made directly or through correspondence, provided that what is requested is something that a created being can do, and that the one from whom it is requested is aware of it in a way that does not involve claiming knowledge of the unseen. Thus, seeking madad from a living person who is present is permissible, but from one who is absent or dead, it is shirk. Therefore, the questioner's statement, "Madad, O so-and-so," is not shirk if their intention is to seek help from them in a matter they are capable of.