I don't recall that, not even allegations to the effect (there were such for Office competitors), plus I probably would have learned of such while working with a guy who had previous interned at Microsoft on IE of that era.
More directly, I'm not aware of any public Windows APIs that handed out data that tricked your code into doing a general protection fault (https://en.wikipedia.org/wiki/General_protection_fault), or in the case of WordPerfect, compel programmers to use their own printer drivers, and write code that regularly drops your tables, figures, etc. to the bottom of your document (unlike the other companies I cited, WordPerfect actually managed to ship a Windows version that didn't GP fault, but that was late, terribly buggy, and prompted all the WP fans I knew to reluctantly switch to MS Word).
My initial search turned this up:
All this stuff happened in the Win16 days, Win32 pertains to NT, and for the consumer market, Win 95 and on (https://en.wikipedia.org/wiki/Windows_API). Win 95 was released in late August 95, by which time all these competitors had fallen by the wayside.
IIRC, Microsoft were using hidden APIs to accomplish this, putting Netscape at a disadvantage.