This an interesting hand. Yes it would have been better that your partner not false carded you with KD lead. But had I been in your shoes I would have done a little trickery and actually sloughed my QS to that KD lead.
Okay, why, so that the dealer even if he had had the AD or trump the diamond. You would hold the JC 9C AS in great shape regardless of what his/your partner did.
I think your partner false carded you so that you would trump high on his KD. I would hate to use the Right bower so early but it put you in a pickle. With two aces, he should have led his left to trick one. And definitely not led a diamond to trick two or false carded you as the dealer most likely will be void in Diamonds with two losers. Your partner could not be loaded in trump because he is leading his aces. A good assumption the dealer has three trumps and probably an ace to boot.
Alternatively, S1 has two approaches that should have used. If S1 does not lead trump first, your partner should have led the AD to the first trick as now he still has AH, KD JS in a better situation to euchre the dealer and get his partner (you) into the action. But that is just how I would have played S1 & S3 hands given the information you provided.
IRISH
All, was playing a game on 3D. Score is 6-9 (losing) I'm in seat 3. I have to admit i was on tilt, so I didn't track all the cards but here is how it played out.

up. 1 and 2 pass to me, I hold
I passed, just reacted, hoping for them to pick up or for my partner to call next. I should have ordered up, I think that was only about 2.0 on BPS but they have 9.
Dealer orders up, so I assume they are 3 trump suits (w/ left) or they are preventing a next loner.
Anyway, Partner, S1, leads

and we all follow suit.
Round 2 they lead

I struggled with what to do, played my

hoping dealer had the

and I can complete the euchre. Dealer overtrumps with
Round 3 dealer leads

my partner lays

and I am forced to play my
Round 4 I lead my

dealer trumps in with
Round 5 dealer plays

which goes and we lose.
So, in hindsight knowing my partner had the left, I should have trumped in with the right in round 2 (
YOU CAN'T ASSUME THAT]. However, what really sent me on tilt was my partner had the

but led the

in round 2. Had they led the ace, I would have thrown off and we would have won.
So was it all on me, or did my partner mess up as well?