In many cases, as I said they don't think about it. They aren't interested in understanding, only in "proving" that they are right - or at least that their beliefs have not been disproven. So they simply don't link the two things. Often they don't even consider the direct implications of their arguments - i.e. attributing all the evidence of age to God quite strongly implies that God is directly deceiving us. But many creationist don't even think that far.
But then there are cases that make you wonder.
One creationist here has repeatedly insisted that the pre-flood atmosphere WOULD have caused accelerated radiometric decay. When challenged to offer a plausible explanation he has only evaded the issue (at best - usually he just runs away). He even claims to be using "logic and reason" despite the fact that he has offered nothing of the sort.
Maybe it's just me but it seems to me that somebody who continually refuses to offer any support for an assertion ought to know that he hasn't used "logic and reason" to support it. But I leave the conclusion to the readers.