There are several issues in play here.
In Shoddy Battle 1, as soon as one team is entirely fainted, the battle immediately ends; no further work is done by the pokemon engine. This is the wrong end of battle mechanics and is also why there are no draws. Anyway, in Shoddy Battle 1, the message that a berry weakened an attack is shown after the health is removed from the pokemon. So, if removing that health causes one team to be entirely fainted, the battle immediately ends, and the message that the attack was weakened is suppressed.
It's unlikely that any of the issues here will be resolved in Shoddy Battle 1, but Shoddy Battle 2 will have the correct end of battle mechanics.
For greater clarity: the attack was weakened, but the message was suppressed.