How can an Electric Slide kill my Deadbeard!!!

While playing as Chomper I was getting triple teamed by these three Zombies. They somehow found me four times out of 5 Giddy Parks. I saw them switch to plants so I did the same when I switched to plants they switched back

to Zombies. So we went back and forth for a bit. I was quicker a couple times and got them. Then my last few attempts I switched to Deadbeard and was launching my bird from the green trash can on the left side just before you go down off the jump pads. Thinking this way they won’t kill me and I can harass them back..... I noticed one of them following me around as they had been tracking me while the other two attacked me for sometime. Didn’t think much of it.. Well once I launched my bird and was down over the cliff to attack the plants at the Zombie entrance the Electric Slide killed me from up in the Zombies base on the trash can. They didn’t just kill the bird they killed my Deadbeard. They only did this once my bird was below. While being hit I could see and hear when my bird received each hit then I would be killed.... How can an Electric Slide kill another Zombie????? I tried to recreate it and couldn’t.