question #1 Sahih Muslim Introduction 75, Introduction, Narration 74 : What are the implications of narrating hadiths from individuals who are considered unreliable or accused of lying?

‘I swore that I would not transmit anything from him or Khālid bin Mahdūj’. [Yazīd] said: ‘I met Ziyād bin Maymūn and asked him about a Ḥadīth, so he narrated it to me on authority of Bakr al-Muzanī, then I returned to him and he narrated [the same Ḥadīth] to me on authority of Muwarriq; then I returned to him and he narrated it to me on authority of al-Hasan.’ [Al-Hulwānī said]: ‘He [Yazīd] would charge both of them with lying [i.e. Ziyād bin Maymūn and Khālid bin Mahdūj].’
Al-Hulwānī said: ‘I heard [Ḥadīth] from Abd as-Samad and I mentioned Ziyād bin Maymūn near him and he charged him with lying’.