The goofiest example of this I ever encountered was having an ad rejected when it was the manufacturer promoting his own product!
Those automated trademark rejections can be appealed in situations where they don't apply.
Suppose the system rejected your ad because it contained the word "apple" which is trademarked. If you were promoting something like "apple pie recipes" that's a usage where the trademark wouldn't apply, and your ad would (probably) be accepted on manual review.
I tried appealing and got one of those stupid Google Knows Best stock choice of questions/answers where they don't let you say what you want to say and then you finish the process and they say Did You Like Our Answer? No!
Let me write out my answer succinctly - give me 20 words if you must but let me write it out!
I'm trying to get a Product Ad showing for #*$! bbbbb cccccc and they say #*$! is a brand (part of - never heard of it myself, might be US brand) so that won't show on Product ads. However, everyone using adwords (direct I assume) has #*$! in their advert. Go figure!