POW and POS blocks appear the same in the wallet for a pool mining the coin -- they show as "generate" blocks. The only way to differentiate between them is to do blockchain analysis and review the input and output of the block and see if the addresses are the same with the same transaction amount with POS interest added.
Yeahhhh - gonna say that they did mess it up, you got this point
however I'm wondering why other multipools(as I know hashcows and wafflepool, maybe more) did not occur the same problem you had...
He didn t pay attention. That was his problem. He assumed it was the same as other POW+POS coins.