Strat-O-Matic Baseball 365

I've never this and think it's actually against the rules. In the game in the Players Championship semis, Yorvit Torrealba is the starting catcher batting ninth for the Bats6. Dan Uggla was the starting DH, hitting 8th. In the top of the ninth, Mathis was substituted for Uggla, but put in at catcher, while Torrealba was switched to DH. I don't believe the DH spot can be moved in the lineup. You cannot start the game as a position player and be moved to DH.
Anyone ever seen this before?

http://onlinegames.strat-o-matic.com/game/348328/624

I'll give HAL the benefit of the doubt. If the batting order came around I bet the pitcher would of actually batted (or a PH).

yeah, not legal for sure in real baseball

Why did HAL even do this? If Mathis was set to be the defensive sub for catcher, he could have easily just come in for Torrealba.