When plotting errorbar plots, matplotlib is not following the rcParams of no linestyle. Instead, it's plotting all of the points connected with a line. As per http://stackoverflow.com/q/18498742/1484957, I'm opening this issue. Here's a minimum working example:

import matplotlib.pyplot as plt

lines = {'linestyle': 'None'}
plt.rc('lines', **lines)

plt.errorbar((0, 1), (1, 0), yerr=(0.1, 0.1), marker='o')

plt.savefig('test.pdf')
plt.delaxes()