I've had this bug once before, a few months ago. In a random battle I was given a venusaur with only 3 moves. Here's the screenshot:

http://www.pokemonshowdown.com/replay/gen1oubeta-16726555
A few Gen 1 bugs:
-Toxic Damage does not reset on switching out.
-Recover Failed.
Turn 6
Redemption is confused!
Redemption used Earthquake!
It's super effective! The foe's Tentacruel lost 87.4% of its health!
The foe's Tentacruel used Rapid Spin!
Redemption lost 3.1% of its health!
The foe's Tentacruel is hurt by Redemption's Rough Skin!
The foe's Tentacruel fainted!
JimTuckins sent out Crobat!
Pointed stones dug into the foe's Crobat!
NOT BUGS
- Rapid Spin does not remove hazards if the user faints from Iron Barbs/Rough Skin/Rocky Helmet damage.
hey not sure if u remember this episode :http://bulbapedia.bulbagarden.net/wiki/Crystal_Onix
but since they did exist can you add a ice/rock type onix and its evolved form a water/steel steelix? it'd be awesome if steelix is water steel :D
For example, if Choice Scarf Jirachi is facing Choice Scarf Bronzong, and Jirachi uses Trick while Bronzong uses Stealth Rock, Jirachi will be stuck using Trick the next turn
http://www.pokemonshowdown.com/replay/hackmons-17934036
Something strange happened causing my dialga to be unaffected by aura sphere.
This is a correct mechanic - Transform (and by extension Imposter) copies type regardless of held item.Also, I've heard transform turns a pokemon into the opposing type of arceus, not into normal type arceus, like it should without a plate: imposter pokemon with a plate switching into arceus probably don't function correctly either if this is the case.
Did your Chandelure have Normalize? It had Skill Swap, so I would think that would cause it.
This is a correct mechanic - Transform (and by extension Imposter) copies type regardless of held item.
upokecenter said:User's Defense, Special Attack, Special Defense, Speed, and Attack stats; gender; types; moves; weight; Ability; and stat stages become those of the target (even if those values are the same). (User is considered to have transformed. Species is not copied.)