It's adamant about the safety of its GMO lines and (in the case of Roundup Ready) the pesticide products that are complementary to them.
It's, OTOH, also a big producer of non-GMO seed and actively markets products to the organic food industry.
When it can't do that, it sues farmers that harvest, plan and grow the seed it wants to protect.
This includes Monsanto's crops contaminating other crops like in the Vernon Hugh Bowman case.
It also promoted (at least in France) round up as biodegradable but we eventually found out it didn't, and went to contaminate the drinking water.
Which is a problem, given that glyphosate based products are currently in the process of being banned in Europe.
The answer from Monsanto to that has been ghostwriting reports and pretend they didn't come from them.
I really doubt your statement.
So if you don't trust Monsanto for most things, you will especially not trust it to tell you the truth about the safety of its products nor about the completeness of their tests to ensure said safety.