Flip flops with multiple clocks
The interviewer was simply mistaken. You always have to think about setup/hold time violations and the resulting possibility of metastability when considering signals passing from one clock "domain" to another, regardless of whether the clocks are "nearly synchronous" or completely asynchronous.

For signals that make transitions at a rate significantly slower than either clock, you can usually use double-FF synchronizers. In other cases, you'll need to use true asynchronous FIFOs, possibly with some sort of flow control or handshake mechanism.