The earpiece is exposed?
That may be splash proof but rating as continuous submersion [sic] is certainly a bit of a stretch.
Of course that's just by looking at the picture.
Even still, before testing with a working device I'd recommend using a dummy phone perhaps with a few moisture indicating strips (cobalt chloride) attached and tossing into the pool. If the strips turn pink, there is definitely some intrusion. If drops are present, watch out!
I like Otterbox Armor series but I've seen them allow intrusion in torture tests (washing machine!) but it could be overpressure of design limits or improper installation, etc.