There's no right or wrong answer to this question, I don't care what anybody thinks. If a judge at the fair only allows knotted items to win because she/he missed the knots, then I'd say those knots are hidden enough to not make a difference.
If I'm crocheting a tight stitch I'll weave, but if it's a loose stitch, I'll often tie a knot and put a tiny pinch of glue to hold that knot from ever coming apart. I've not had any issues. Far as using glue after weaving in ends, I will use that on occasion not because I'm afraid the ends will come out and unravel my piece, rather because the very