not really dude… testing standard operating functions (that werent changed) is also part of the usual QA process when doing system-wide changes like OS upgrades etc.
especially something as common as FUNC + knob… considering how often people use this
at least it will show if its always happening, rarely happening, never happening… etc… for all i know these bugs may be sourced somewhere that results in different effects on each unit - who knows, but what I can say is that the bugs were noticed almost immediately after trying to resume normal operation - and the TYPICAL standardized QA procedure would easily reveal such things