GISAT was the most sophisticated satellites after cartosat 3
1.GISAT-1 was repeatedly delayed and then it's launch failed.
2.GSAT-11 was hurriedly called back,even after Tapan Mishra assuring there is no need for that.
3.Even after having LVM-3, I-3K sats are still launched from French Guiana.
4. RISAT-1A's resolution reduced compared to RISAT-1
5.Tapan Mishra's proposal for more efficient High Resolution Sat with light weight camera was rejected (his proposed sat would have weighed less than 300Kg,but with similar resolution to Cartosat-3 class)
6.He was poisoned, he was sacked as director of SAC
7. Tapan Mishra claimed that higher officials of ISRO planned to sabotage HTS program to favour a foreign HTS satellite
8. CY-2 lander's configuration was suddenly changed and then it was launched without proper testing. ( I don't remember who,but someone claimed that they suddenly changed the configuration to delay CY-2 launch to post 2019 elections, they thought mudi would loose elections so that this launch can be done for the new govt).
9.now that particular ISRO scientist claims that a relative of former Chairman involved,
I really pray that I should be wrong here, but all of this points me towards Dr. Sivan.