They are suggesting that the JVP was running the government alongside Mahinda, which is incorrect because Chandrika, not Mahinda, was the head of the government at the time.The clip doesn't say anything about any deal with Mahinda, but simply asks whether JVP was in the government with Mahinda. So, yes they were. If not, tell in which time were the JVPers functioning as ministers earlier?
The actual question wasn’t whether the JVP was part of Chandrika’s government at the same time as Mahinda—that is common knowledge. However, you’re free to reframe the narrative if it suits your argument.