With JMM, you just never know. Not saying anything negative, they've just been investigated a lot over the years and you just never know what goes on behind closed doors... or gates as the case may be.
As for the security there, that's pretty much standard these days not being allowed onto the property of large corporations. Ever since 9/11 security has tightened everywhere... try to get in at Monsato, Pfizer, Boeing, Rams Park, etc.. around here... you can't! Security stops you at the gate and you must be verified to even enter the grounds (trust me, was in sales/recruiting for ever before having my little ones). So I don't find that strange in the least that they're that secure.
Who knows what really happened that day, but early signs sure point directly at one person right now.