Consistency
Same person, 2 different sieges, within several seconds of each other and my wyvern loss was the first raid, but they didn't have time to change relics/crystals anyway - Castle defense is 0 (bot castles)
My Wyverns are currently 1600 each, which means 2 golems would need to be 800 each to kill one of my units (roughly) which is possible but I think he would need to have most defense bonuses up + relics... But then that still doesn't explain why in the exact same situation only seconds apart it would lead to a different outcome, neither of us had paragon on and as mentioned, unless he was swapping relics/crystals at the exact moment I hit the first castle, he didn't have time to react. Additionally i kept the resources in as extra evidence of the timing, I was unable to go over 50k + because the raids were so close together.
Additionally a site I have always used for calculations (which has very rarely been inaccurate) has said that I shouldn't of lost a wyvern, Plarium's response to this will be, we use decimals to calculate losses but that really isn't correct for this specific situation. I have seen several things like this occur in the past, most notably with BG's magically spawning/despawning units
http://stormfall.playtamin.com/?attackmode=1&attackmode2=1&attackmode3=1&a15=85&d9020=2