When Evil Hal protests taking Matt with them to the Badlands. This is when Hal was completely evil (basically Karen pulling the strings), and every nice or “normal” thing he did was for tactical purposes only. However, he would have gained nothing as Karen’s puppet from banning Matt from that mission. It wasn’t even a particularly dangerous mission, yet he still insisted that Matt stay behind because it wasn’t safe. You could argue that he was just trying to act like regular Hal, but then he acts noticeably shady for the rest of the episode. Basically, this is Evil Hal trying to protect Matt for no other reason than to keep him safe, which is as regular Hal as it comes.