When a bid is less than the reserve the amount shown is just enough to beat the next highest bidder. The $23+ met the reserve so his previous bid was shown at it highest amount. When he withdrew that bid the lower bid dropped to just enough to beat the next highest bidder. Probably not stating it very well but ....
Seems the new reserve is $19,848 and the high bidder is not the person that withdrew their bid. Ah, the intrigue.