They were maladroit enough to attack him on his least vulnerable side, summoning him before the privy council to answer to a charge of receiving bribes in the administration of justice. How would you define maladroit?
The term proletariat is used in Marxist theory to name the social class that does not have ownership of the means of production and whose only means of subsistence is to sell their labor power for a wage or salary. Proletarians are wage-workers, while some refer to those who receive salaries as the salariat.
But Marx's quick one-paragraph (Section1.46) dismissal of the lumpenproletariat makes it clear that by proletariat he specifically means employed workers. After all, elsewhere in the Manifesto, he defines the proletariat as a class of labourers, who live only so long as they find work, and who find work only so long as their labour increases capital.