I am sure I won. The auction was supposed to end a minute after I posted.
And my bid delayed the ending point by 15 minutes.
Kaechi's bid came 27 minutes after mine, at which point the auction was effectiely over.
To get into details,
The auction started at 2:49pm, Sunday (GMT+9), and was supposed to last 72 hours.
Therefore, it should have ended at 2:49pm, Wednesday (GMT+9).
I made a bid at 2:48pm, which delayed the ending point to, 3:03pm.
Kaechi bid at 3:15pm, at which point the auction was already concluded.
Please refer to PRO trade rules.
https://pokemonrevolution.net/forum/topic/29538-overall-trade-rules-forums-and-in-game/