Continuity mistake: When Blade is fighting the henchmen near the end, he lifts the last surviving one into the air and you can see Blade's hand through the henchman's throat and it is obviously a dummy. Then, when he falls backwards, his hand is not on his throat, it is on the henchman's shoulder.
Continuity mistake: When Scud gets blown up there is only dry pieces of him that go everywhere, surely there would be blood as well.
Continuity mistake: When Blade meets the Bloodpack for the first time, everyone is introduced by name. When they introduce Snowman (the swordsman), he does a gesture with his right hand. In the very next shot where they show Chupa, Snowman's hand is already back to the handle of his sword. He may be fast, but he's not that fast.
Answer: In Blade I we saw that with sunscreen and the avoidance of direct exposure Deacon Frost and his lackeys could go out by day. The reapers are probably two or three times more sensitive than normal vampires so the exposure was probably not long or direct enough to kill the regular vampires.