I think you two are talking across each other, he's saying that if you lift properly it's not easy to get injured, and you're not saying that it's easy to get injured deadlifting properly but that it's easy to deadlift wrong and therefor get injured.
It's really quite rare that someone is deadlifting wrong the first time because they don't have the flexibility to do it properly compared to doing it wrong because they didn't ask for the right kind of help.
Even bomb disposal can be a safe thing if you do it perfectly right :). I think the issue (when you take off the coat of semantics) is that it's easy to do it wrong and injure yourself.
It's really quite rare that someone is deadlifting wrong the first time because they don't have the flexibility to do it properly compared to doing it wrong because they didn't ask for the right kind of help.