and for consistency's sake: what exactly are you referring to when talking about "destruction of BS"? some sort of "naval battle"? that's interesting, because no one can say anything about "it" - animation representing "battle" is purely symbolic, just as well as tank sprite doesn't mean it's a "one tank"; therefore the only things we know for sure are:
#1 - some segment of player's naval forces has been engaging enemy ships in certain sector
#2 - engagement lasted for certain amount of time, for details please refer to lenght of turn in given historical period
#3 - combat log consists some abstract data, regarding amount of damage inflicted and taken during given time, which we can refer only to amount of hammers used to build "Battleship" and to it's combat chances in next engagements, no more clues were given - we can't say HP refers to ship's overall effectiveness, crew status or amount of ammo left -
nothing here
#4 - message "Frigate destroyed Battleship" is far from detailed; we haven't been provided with details of engagement, and any attempts to translate combat log into volleys are rather hilarious blind-guessing with no real substance; for what we know "destruction" could have meant "1:1 combat", trick, sabotage, mercy killing after some heavy malfunction, yadda yadda yadda - with no knowledge about details assuming any conceivable answer to be "one true and holy" is simply guessing and playing with %%% with no real rules for counting them;
#5 - we know nothing about order of battle, nothing about amount of enemy contacts, shots fired etc - our imagination is restricted only with assumption that: armed forces represented in game are of human origin, follow some guidelines when it comes to historical development and that numbers present in game may or may not relate to reality - if they relate, we know nothing about such particular relation - ie. no one can say 1 HP represents 100 soldiers;
conclusions:
if you were for some reason misled by silly animations and assume one Battleship and one Frigate/ whatever, 100 BS and 100F if you want/ fixed their positions and fired some volleys at each other then you are indeed living in "la-la-land" because you have as much data to prove it as have people assuming Battleship exploded due to sabotage and "as much" means - none; you can argue all night if sabotage was possible, if possibility reflects this 0,5 % in combat predictions, also - if sabotage was more probable than engine malfunction, mutiny, or in extreme case: frigate disguising as merchant ship or ignored by crew, firing on supply ship filled with ammo right next to BS - the point is you can only say destruction of Frigate in 1:1 combat seems more probable - how much more is hardly relevant as no one can precisely say and the common sense is 99% winning chance is doing quite good job on this matter;
throwing away vast amount of accidents, random encounters, vis maior, and other events not covered by "two sprites shootin each other" just because "i think it happened that "right" way" is only another way of baseless assumptions and worshipping self-invented imaginary "reality" 
for what we know "Battleship" is lost, it's pretty rare in such conditions (combat predictions), we have endless set of possible explanations for unusual event - either have some fun, use imagination and stick to one of those or just forget about it and build another one
convincing everyone that "this is ahistorical" is pointless because no one has any idea what and how happened except above facts; of course if you want to convince someone that "certain battleship would sink certain frigate in direct combat in certain situation", have fun and disregard what i wrote
