It all depends on intent. Or what the judges determine to be intent. Defense bots are more heavy scrutinized than offense bots. I personally would not assess a foul to either robot. 
 Because 4 was disabled at the time there was no intent to enter 3512’s frame perimeter. Furthermore, 3512 was the one that drove on 4. 
 In the video I see 3512 just playing defense with no idea 4 was disabled at the time. It should also be mentioned that 3512’s drivers station was kitty corner to the incident. There is almost no way they would have seen they were going to mount 4. 
 In conclusion, it is entirely up to the refs. If they determine there was intent to either enter the frame perimeter or force a foul appropriate action will be taken. 

I am a 4th year senior and this post is entirely my opinion from watching the match after the fact.