You don’t need to be psychic- just check a good security site like http://krebsonsecurity.com, which reports which browsers (if any) are affected by security vulnerabilities and zero-day malware attacks at any one time.
Of course there have been occasions when certain browsers were affected by in-the-wild malware attacks- yet Bob continued with his “all browsers are equally safe” fallacy, or the equally false “only surf legitimate sites and you’ll be safe” misinformation.