My Friend Had An Injection On His Forearm That Cause

my friend had an injection on his forearm that cause purple IMMEDIATELY after followed shortly by swelling that I am hardly use to seeing. It is more than apparent the purple is blood and to my assumption from the vein being torn. The swelling isnt a bubble like swelling, but is more geometrical like a hexagon. It is hard and white seeming like it is keeping the blood from spreading any further from my uneducated opinion. "

this all happened immediately following injection.