I don’t think there was anything wrong with your overall plan: just smashing with untargetable flying mimics is perfectly workable IMO and if you’re already ahead (as you were) you don’t necessarily need to go Growth and I think there’s a real risk in adopting a slower, more passive strategy after putting so much into getting ahead to begin with.
If I had been in your shoes, I probably would have gotten the Rhino with your first CoL: 7 attack (8 with mid-Midori!) is as good as deathtouch anyway plus you get all that health. Your turn 5 patrol letting me get a kill on Cal was a problem: if you had summoned and maxed Arg instead of Cal and CoL you would’ve still had your anti-air unit but also a midori-buffed wisp, the young treant as a blocker, an extra card, AND an additional gold of float. That’s a lot of upside. You definitely shouldn’t have workered T-Rex: he was your win condition and he could absolutely still turn the game if you had him in your deck.
All in all I don’t think there were any big mistakes from you (or, like, great plays from me) that swung things, just a few minor ones that compounded with some luck of the draw (me always having Sensei’s Advice when I needed it most) that let me keep things close enough until my Archon arrived.