There are many reasons that this couldve happened.
Your Machop could have had very low defense stats, somethnig typpical in fighting types.
Lioone could have a very high attack stat, or maybe it used a move before that raised it's stats.
Lioone could have had STAB.
basically, its very doubtful that there was a problem with your virtual father's Lioone.
Source2: I battled the Lioone myself recently