Bad spark plug damage to coil pack?

I was replacing the spark plugs and coil packs on my engine because there was a misfire and i thought they were they cause, in the meantime i discovered it was actually due to a vacuum leak but since i already had them and the ones on my car are very, very old already i went ahead and did it. When i started the engine i was surprised to realize it was once again misfiring but this time it was much worse than before so i went ahead and changed back to the old coil packs and plugs and it worked normal. Upon inspecting the new plugs with a multimeter i found on of them was in open circuit and the electrode even moved around. My question is how likely is it the bad spark plug damaged my coil packs? I must have left the engine running about 30 minutes with them so im worried they might have overheated or something. I tried installing the old spark plugs with the new coil packs and it seemed to run fine, i took it for a spin and did a few 0-60 runs and took it to the redline and after that it had a small misfire but i think that might be due to the spark plugs since they are very old and not in such a good shape.