That is a very good point. There should be a だ if it was indirect qotation. The da cannot be dropped and since it is a news cast they wouldn’t drop anything either way. They wouldn’t have dropped the い in the other example either. It’s like in english news you wouldn’t use “wanna” for “want to” probably ^^.
There are however other grammar points that have the construct ものと as part of them. It would also make more sense why there is a mono in the the first place at the end of the sentence.
My bet is currently on https://japanesetest4you.com/flashcard/learn-jlpt-n1-grammar-ものとおもわれる-mono-to-omowareru/ (alternative link https://jlptsensei.com/learn-japanese-grammar/ものと思われる-ものと見られる-mono-to-omowareru-meaning/)
But you have to understand that it is an incomplete sentence and you are not NEEDED to know how the sentence ends because the first part carrys the important meaning. Its not that important if they said it or speculated it or wrote it in a newspaper article. The important part is “WHAT” was said/written/assumed.
Also get comfortable with japanese being vague or having double meaning sometimes. That’s just the whole stick in japanese with being context dependent and I think one of the great joys of learning this language 