This in itself isn’t an indication of a false claim. It depends on what grounds they are claiming. I haven’t read this particular post so I don’t know what level of benefit this person is claiming but it’s absolutely possible to be able to walk in this manner and still qualify for even the advanced rate of PIP.
For all activities, including mobility, the assessor has to consider whether the applicant can complete it safely, reliably, repeatedly and in a timely manner.
Safely means without exacerbating their condition or causing injury to anyone else. Reliably means to an acceptable standard. Repeatedly means as often as necessary throughout the day without having a knock on effect on other activities assessed, and in a timely manner means in less than twice the time it takes a non disabled person to complete the same activity. The assessor has to consider how many times the claimant has to stop and rest, and for how long, and they also have to consider any pain or breathlessness the claimant experiences as a result of doing the activity, as well as any pain or other medication necessary in order to complete the activity.
I wouldn’t know this level of detail about any of even my closest friends or family.
Unless you are qualified to assess whether all of these things apply, and you know what level of benefit has been awarded and for what reason, you have absolutely no way of determining whether that claim is fraudulent or not and you run the risk of reporting someone and triggering a review of their benefit when in fact, they haven’t done anything wrong. There’s a reason benefit assessors are healthcare professionals. There’s also a reason why they are trained and fully versed in PiP rules and how they are applied and interpreted. Unless you are trained to the same standard, you really aren’t qualified to judge.