I wouldn’t suspect it, bugs caused by multiple effects running parallel really only started with the debut of Lycanthropy Gems (and other Heroic Gems which “float” across the board) as their effect doesn’t actually trigger until the floating effect finishes, which (depending on specific timings) can cause certain things to occur out of (intuitive) order.
Or maybe you’ve heard of the manual-target-softlock bug? If you spellcast while such a Gem is still floating then the Gem hitting its target would disable that troop from the list of available targets highlighted by the UI, completely softlocking the game if they were the only valid target. (Last I heard, it’s actually still possible to trigger in current versions)
There’s also been a few cases of spell effects being impacted by game speed, but those are extremely rare.