Team A commits illegal touching, Team B fumbles, Team A recovers and runs...
Team A can still keep the ball following illegal touching, if Team B commits a foul while Team A has the ball, since such a foul would be penalized from the end of the run... as long as there exists an end of the run.
But if A88 takes the ball to the house, across the goal line and down the tunnel like Forrest Gump, then there is no end of the run. Any Team B foul committed during that run would not be penalizable, unless it was a PF/UNS. Because there is no possible point to enforce it from.
Here is a contrived example of when, in the words of 10-2-5-a-2, "enforcement is made possible by illegal touching of a kick," and when it isn't.
A punts. A0 illegally touches the rolling kick at the B-20. B0 recovers the kick at the B-20 and runs to the B-45 where he fumbles.
Then A11 recovers the fumble, but fumbles at the B-40.
Then A22 recovers that fumble, but fumbles at the B-30.
Then A33 recovers that fumble, but fumbles at the B-20.
Then A44 recovers that fumble, but fumbles at the B-10.
Then A55 recovers that fumble, and a) is tackled at the B-2, or b) scores a touchdown.
And, B99 committed some kind of holding foul at some point during these shenanigans.
Normally, B99's non-PF non-UNS penalty would be declined by rule. But here, enforcement could be "made possible by illegal touching of a kick." When and how?
If B99 fouled during A11's running play, A can accept the penalty. The end of the run is the B-40. It will be A's 1/10 @ B-30.
Same deal if B99 fouled during A22's running play, A33's running play, or A44's running play. It's A's ball after marching off 10 yards or half the distance from the end of whichever run.
If B99 fouled during A55's running play, then in a), it's the same story. The penalty can be accepted. A's 1/G @ B-1.
Only in b) can the penalty not be accepted at all. Because A55's run did not end. There's no place to enforce the penalty from. Instead, it's declined by rule, and Team A doesn't get the ball at all. It's B's ball at the spot of the illegal touching.
It's not very intuitive, with or without the ARs. The upshot is: the only time A gets screwed is during the very last run, the one that scores the TD. During any previous running play, there's a place where we can enforce the penalty.
(It's not very equitable for A to lose the ball altogether just because A55 succeeded instead of failed at crossing the goal line, is it? But that's another story.)