He got the spray off and could have killed her if he wasn't a fuck up and had something truly toxic.

In other words, this was an assassination attempt by a fascist against a political figure. His assassination attempt failed because he is a drunk fuckup, but plenty of assassination attempts against Castro were also failed attempts by equally incompetent gusano fuckups. However, those attempts were taken very seriously by Cuban counterintelligence no matter how unlikely the attempts would actually succeed. I do not see the same sense of urgency and seriousness here.