I strongly believe distraction works best at 2 yo. Even if you gave him a time out (2 min) he would be back at the refrigerator once he's let back up. It's the nature of a 2 yo to be persistent. He has to figure out that door and besides it's so much fun to knock things out. You have to keep taking him away from the refrigerator until he stops running to it.
His brain is not developed enough to associate the time out with the activity. He isn't able to "say" to himself if I do this, I'll get a timeout. When time outs work at this age it's because they are themselves a distraction.
I suggest that the reason your mother's efforts didn't work is because the distraction wasn't active enough and perhaps because she didn't physically keep him out of the kitchen. When we use distraction we need to physically separate the child from the scene so that his mind latches onto something else equally as interesting.
You navigate this with your mother by keeping an open mind and by reading up on various ways to discipline a two year old. Talk with her when you're not dealing with your son. I suggest that the two of you can use two different ways of discipline. You can try out time outs while your mother is using distraction. Look at the way both methods play out. You try out distraction too. See what works for each of you. You both do not have to use the same method. What matters is what works for you.
Later: Telling the child no or in some way that they are not to do what they are doing is a part of distraction.
