Second, some math.
Suppose both Supa and Pie are telling the truth. If TPs are counted separately from town, then there is likely one mafioso, making it 6-1-2 rather than 5-2-2, which seems unlikely because we would be in LYLO in DP2. That is possible. If TPs are counted as town, then there could still be two mafia, making it 7-2. So it's not impossible that they are both telling the truth.
Third, some behavior analysis. If Pie is mafia and he read the first post of the DP, then he would have known that there was at least one TP. Thus, he would have known that he would get CC'ed by the actual TP. I doubt he would have done that. Of course, it is possible that he didn't read the first post carefully and missed that. If Supa is mafia, this seems like a bizarre play. If Pie is actually a third party and Supa is mafia, then Supa is setting himself up to get lynched next DP. That also doesn't seem likely.
Fourth, some WIFOM. If either Supa or Pie is mafia, then they could have noticed that That2 said "at least one TP" and gambled that town would be willing to accept that there would be more than one TP. So it's possible that one of them is mafia taking a risk. It seems like an unnecessary risk to take, though.