When Detective Joe West and three SWAT members try to arrest Bivolo in the storage facility, West orders one SWAT member to handcuff Bivolo. He starts to move towards Bivolo and is shown doing so when the camera angle changes. After the angle change, to show West, the SWAT member whom we saw move towards Bivolo is still standing next to West, where he was before he started to move.
When Barry picks up Falicity's purse after she removes her flaming shirt, Barry turns to see Cisco and Caitlin watching them. Camera changes. Barry hands Falicity her purse, THEN turns to see Cisco and Caitlin, reacting as if noticing them for the first time.
Cisco refers to Oliver's bow as a recurve; however, starting in season 2, Oliver switches to a lever action bow, which is considered a type of compound bow. He uses an Oneida Kestrel. It is really a hybrid type of bow that allows to snap shooting of a recurve to be combined with let off of a compound.
Barry's padding for getting shot in the back gives him an obvious hump.
When Oliver begin training and they walk over to Oliver motorcycle you can clearly see that there are no crossbows on the ground. However, immediately following the scene, Barry gets shot with two arrows and you can see the crossbows have appeared.
Felicity traces Captain Boomerang to Central City based on the presence of iron oxide on his weapon. Iron oxide is pretty much rust, which is found in abundance everywhere and would in no way be unique enough to serve to pinpoint a place of origin.