One time usage is not gonna kill you since it will have hardly any impact on Hct and platelets.
I have not tried it personally, but based on what I have heard from both Bostin and Nick Trigelli, there seems to be an immediate effect after injection in terms of pump. Take with a grain of salt though, they are both meatheads.
Based on a quick search it seems that EPO increases NO production acutely but blunts it with chronic exposure. So it may well increase pump and vascularity after isolated injections.
https://www.ncbi.nlm.nih.gov/pubmed/15450363
http://hyper.ahajournals.org/content/hypertensionaha/33/3/894.full.pdf