If the fabric ripped today, that would be a spectacularly unforeseeable and unlikely event. It wouldn't make me wrong. Fact is, the odds of a catastrophic rip -- much less a spontaneous rip -- are very, very low.
Further, just because all air-supported domes use the same technology doesn't mean each dome is of the same quality or has had the same life. All pants have the same technology, but if I'm worried about them splitting, I'll take the higher-end ones that have been hanging in the closet for most of a decade over the bargain rack pair that have been worn four days a week by the 300-pound man for a last few years.