What about the claim that the sun once stood still in the sky for a significant period of time? Is that a historical fact?
A better point would be the Resurrection. Should we base our inheritence laws on the possibility of resurrection? Should biology assume ressurection? Of course not. The Resurrection is a miracle. A purposeful suspension of the laws of nature.
The Sun/Earth/time suspended for Joshua would also be a miracle.
If God can create the Earth he can suspend time, raise the dead or break His own laws of nature when He sees fit.
And He does these things at times so people will believe in Him. But as the Bible says most people will discount the probable and choose not to believe in God.
Science, of course, should not assume miriacles. People should, however.