Trying to add or offset lap time due to tows is not proper science. Verstappen already did a 23.4 in the banker lap without the tow and then did 23.4 later with the tow. If a driver sees that he is up on the previous lap before T1, then he can choose to manage the lap differently. Without the tow, he might have simply been more aggressive again into tamburello to compensate. Perhaps he thought he could save the tire a bit in tamburello with the negative delta already leading up to it. We can't know how a lap without the tow would have played out. It is not simply "add 0.13s".
Verstappen said last weekend:
If my mom had balls, she'd be my dad
It is perfectly apt here. The only thing we do know is that Verstappen is on pole with a brilliant lap. One must accept this.
A lion must kill its prey.