Single Oversized Chip
The dealer rules it as a raise and the big blind explodes, saying, "He didn't say anything, he has to announce raise!" and calls for the floor. The floor rules that the 500 chip is a single oversized chip and it's taken as a call, as there was no announcement of the intent to raise.
The small blind tilts, claiming he wanted to raise, and moves all in when the flop comes


.The big blind insta-calls and tables

.The small blind has

.The turn card is the
and the river is the
giving the big blind a full house. The small blind is down to 600 in chips.