First, they killed me trying to sneak up on them in tunnels north of the water around our (blue base). I thought this was mildly suspicious because I hadnt made noise in half a minute and was sneaking up on them). When I respawned I went looking for them and killed them in the exact same spot. I took the intel, joked with them about bringing it back to them and then followed tunnels to the entire other end of the map to make a similar water crossing myself. Their tent was at the back edge of their island with scattered walls along the edge giving me cover. I made the crossing safely at a sprint and was happy to see all the kills in the queue were being made by greens, so no one would be respawning in their base. Then, I see the text ‘stardust_s’ has changed teams’. I see this when I’m pretty close to their island (close enough I consider myself ‘safe’ behind the walls and only a few seconds from the health tent. When I’m literally about 3 seconds away and planning my jump up, I get headshotted by Stardust_s. Of course they find this hilarious.
TL;DR, Stardust_s switched to my team to mine on r1ctf and switched back when I was a few meters from returning the intel to kill me. 2 instances of behavior with the earmarks of aimbotting.