I don’t think OJ had to resort to any trickery. Gloves that aren’t worn for a while shrink and get stiff. And he had latex gloves on his hands. Its no surprise they didn’t fit.
Hell I wear exam gloves every day, and THEY often don't even fit!
Now trying on a pair of leather gloves with OJ's blood soaked/dried into them and boy, you're going to have a problem getting them on.
I remember one person commenting at the time: " Its a GREAT example of why OJ is innocent. Everyone KNOWS that you need to be wearing perfectly fitting gloves when committing a murder!"