I don’t doubt that a trained Marine would conclude that an operation as described by the media would be difficult to pull off by an individual, even a trained one. One aspect that bothered me was the tear gas canisters he allegedly tossed in. It’s not an item that civilians can typically get off the shelf, unless he made it himself.
I just did a search on google and it gave me different results for tear gas grenades. I can’t click on the links b/c I am at work and my web filter won’t allow me to. But they are available.