incorrect, receiver wallet is atomic wallet , cannot spent unconfirmed tx. just tell me if there any possibility that he used tx accelerator ?
Charles-Tim answered you correctly.
The fee rate used in the transaction you shared in the OP was 2.21 sat/vbyte.
One of the outputs was spent in
this tranaction with the fee rate of 108 sat/vbyte.
The total (virtual) size of these transactions was 368.25 vbyte and the total fee was 24,574 satoshi. So, the combined transaction fee was around 66.7 sat/byte which was enough for a fast confirmation.
That's why both transactions were confirmed in the same block (776342).