Resin holes

I made some letters with the alphabet mould and put dried flowers in first and then resin with gold leaf added when I demoulded them some had small holes on the edges and a couple had gaps and like chips where there was no resin at all. Do you think it was bubbles trapped underneath? I’ve done it before with the resin in first and they turned out fine but I have seen it done on you tube where they put the flowers in first. Maybe I purposely too much in? So there wasn’t enough room for the resin to move under? Please help