I didn't notice this before the weekend, but the Tar Patch debuffs are now lasting long after the Tar Patch ends, and after the mobs leave the Tar Patch. Not all the time, but some part of the time, the debuff will stick to the mob, and not be limited to the Tar Patch duration/AoE. It seems to be working exactly like Freezing Rain now, w/ a chance the debuff will "stick."
I tested my Dark defender, and teh CoH Tar Patch was not working this way - AFAICT, I might not have been testing long enough. It seems to be just Corrupter Tar Patch, and maybe the Mastermind version (don't know offhand about Masterminds). So is this an undocumented change, or a bug? Or a documented change I missed?