I'm confused - so, were two US troops NOT stopped - and Mexican officials did NOT take a service pistol from one of the Americans ??
The POTUS outruns his headlights on twitter more times than people can count - but Fox, Newsweek, Army Times, and CNBC have all reported on the incident. Resolved peacefully under the explanation that the Mexican force were unclear about the true location of the border - but the fact remains, armed Mexican troops disarmed two American troops on the border because they "thought" the Americans were in Mexico.
I did at least a few days near the border throughout the 1990's doing JTF-6 rotations and shitty Mexican "security" supporting Coyotes and Drug smugglers directly or indirectly by causing diversions or by just looking the other way is hardly a "stretch" of a claim.
Post it over twitter? Sure - sophomoric tweets are a constant source of WTF moments but overall, fuck Mexico
They have been providing direct and indirect support to thugs on the border for decades - I don't think the POTUS tweeting about it erases decades of suspicion.
Proof? I don't have proof of either direct or indirect support but I don't need a rock dropped on my head as proof that boulders are hard and heavy either.