You will recover HP/MP in passive mode as long as you aren't actively creating hate on the mob. (and standing still)

the patch notes say incurring. INCURRING. ING
not
incur,incurs or incurred. it's ING

Players will not automatically recover HP and MP when incurring enmity.
thats the quote, now lets interchange the word Incurring with acquiring. They mean the same thing.

so does it say:
Players will not automatically recover HP and MP that acquire enmity. ?
or does it say:
Players will not automatically recover HP and MP when acquiring enmity. ?

because those two sentences have two completely different meanings.