Im not against on what OP said but on Mr. SHAWN-MIDWAYS case its clear that he commited Plagiarism.

Nobody is perfect sometime's we all made a mistake like the second example you give on Mr. iasenko its obviously a mistake that is why he dont get banned.

Sometimes the reason for this cause is lack of sleep or if you already reading for a long time on your screen or especially when you are on your phone because its hard to select text on phone.