Which is absolutely typical of being over-weighted.
The diver has to compensate for superfluous weight by adding a greater volume of gas to his BCD/drysuit.
On A-scent, that greater volume of gas expands as per Boyle's Law. Positive buoyancy results much more quickly and dramatically, especially in the shallows - where ambient pressure reduction is most significant over a small depth.
For example:
From 10m/33ft to the surface the pressure valves (2ata - 1ata) which means any gas in the BCD/drysuit doubles in volume and, consequently, positive buoyancy.
A proper weighted diver with, maybe, 1 liter of gas in their BCD/drysuit will notice an expansion to 2 liters of gas.
1 liter of gas volume equals 1kg of positive buoyancy in fresh water.
The total buoyancy rise is only 1kg. It's easy to compensate for 1kg increase using the lungs...and simple to quickly dump 1 liter if gas from the BCD/drysuit.
In contrast, an OVERweighted diver with, maybe, 5 liters of gas in their BCD/drysuit will notice an expansion to 10 liters of gas.
The total buoyancy rise is a massive 5kg. It's hard to compensate for 5kg increase using the lungs...and very hard to quickly and accurately dump 5 liters of gas from the BCD/drysuit.