Ive use skint before. I guess same material 3M decals. Yup I put it on my HP notebook no residue left behind. But peeling it off is about tricky as it gets. At one point I thought I rip off the top panel off the LCD.
All I had to do was stick my fingernail under a corner and start peeling, using my other hand to keep the lid shut. At no point did I feel afraid I'd rip the computer open.
Could it be that your decal wasn't actually using 3M adhesive, but rather some off-brand?