An investigation yes, dangerous , no.
Well, this whole system, or at least this instance all depends on the second aircraft to actually are what the first one is doing.
It's the last hole in the swiss cheese. I can imagine a day with fine weather but a wet runway from earlier rain, with the preceeding aircraft blowing all the water behind him, creating a local mist. That might obscure the RTO Just long enough so the second aircraft can't stop in time.
A heavy 777 needs way more runway to stop than an e190.
I'm not saying it is dangerous, but not saying it should be normal, but hopefully the Investigation will look into this.